Easter%20Island:%20Multiple%20Lessons

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Easter Island Multiple Lessons

• Environmental Suicide (Diamond) or something
  else?

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Very Isolated
Easter Island was annexed by Chile in 1888. It
lies 3510 km west of the Chilean mainland.
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Easter Day in 1722

• Imagine what the first Dutch explorers
• thought when they first accidentally
• sailed to Rapa Nui (Easter Island)
• and saw the statues.

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Statistics

• Rapa Nui (Easter Island)is 5 hours (3600 km) by
  jet airplane from Chile (2000km from the closest
  inhabited island).
• The island is triangular and about 20 kilometers
  long. (27S)
• Some statues weigh over 100 tons (the largest
  were close to 10 meters high).
• Hundreds (887) of statues all around the island.

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How did it fall apart?

• There is clear evidence that Easter Island once
  was a heavily populated (perhaps 20,000 people)
  and rich society.
• In 1772 the population was estimated at 2500
• There is clear evidence that this big population
  collapsed and most of the population died.
• Collapse triggers? Natural or Culturally
  induced?

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Collapse Generic Story

• Natives came originally from Polynesia -probably
  accidentally found Rapa Nui (Easter Island) while
  they were lost.
• Statues were built by natives cut from soft
  volcanic stone on the island.
• Society collapsed before the Europeans arrived
  caused by overpopulation and poor use of resources

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Geography
Roughly triangular in shape with complex
topography (locally isolated valleys) and has 3
major volcanoes.
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Settlement of the Pacific Islands
1000 B.C.
600 A.D.
500 B.C.
600 A.D.
1200 A.D.
800 A.D.
900 A.D.
The Pacific Islands were settled from the
northwest, probably from Asia and Melanesia, in a
series of waves in westerly, then northerly
(Hawaii) and southerly (New Zealand) directions
But maybe 400 AD and this is crucial to collapse
interpretation
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Moai

• Easter Island has hundreds of large stone statues
  (moai).
• 13-32 feet tall
• 10-87 tons in weight

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Thriving Population

• Evidence suggests that Easter Island had a large
  and rich thriving society.
• Many house foundations (enough for 20-30K people)
• Agricultural Intensification (large composting
  pits, water dams, stone chicken houses, stone
  windbreaks) suggests a lot of food was needed and
  grown.
• Society was broken into
• 11-12 territories or clans
• (requires a critical mass population
• For such fragmentation. ?
• 800 people per square mile.

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No Collapse

• Rapa Nui (Easter Island) must have seemed like
  paradise to the first natives of perhaps 100
  people.
• Forests
• Seafood
• Plenty of space

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Clues to Deterioration

• Pollen in soil samples can show how plant life
  changes over time.
• Bones of animals show that less and less fish was
  eaten as time advanced.
• Bones of humans show evidence of cannibalism.

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A statue based economy

• Constructed in 3 waves 1100 A.D.
• Statues grew larger and more elaborate as time
  went by ? some kind of clan one ups-manship ?
  fairly weird
• Economy centered around statue building
• Many roads
• Clan based niches in statue production
• Food production concentrated to free up labor for
  statue construction

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Why so zealous?

• The stone on Easter Island is the best carving
  stone in the Pacific
• Society was isolated, so the energy expended in
  other Pacific societies (trading, raiding,
  exploration, and colonization) was directed
  inward
• Chiefs got stature not by inter-island
  interaction but by competing for status by a game
  of statue one-upman-ship
• Later ones had a pukao, or large stone hat
• Clan based society, let each clan specialize so
  while each group had a monopoly on some item,
  trade between groups was the norm.

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Statue Physics

All these methods require the use of Logs
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How were they raised?

1. Transport, Raising, and Food Production issues
   suggest that many trees were cut down to provide
   for statue production and to clear land for food
   production.
2. When discovered in the early 1800s there were no
   trees on Easter Island
3. Did Deforestation lead to the collapse?

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An Abrupt end

• Statue building, and the complex Easter Island
  society ended abruptly about 1600 A.D.
• Incomplete statues still embedded in quarry
• Total number of moai on Easter Island 887
• Total number of maoi that were successfully
  transported to their final ahu locations 288
  (32 of 887)
• Total number of moai still in the Rano Raraku
  quarry 397 (45)
• Total number of moai lying 'in transit' outside
  of the Rano Raraku quarry 92 (10)
• Stone carving tools left to lie
• Chicken houses abandonded
• Roads left in disrepair
• What happened?

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Collapse Standard Scenario

• Forests Gone
• No trees on island when discovered by Europeans
• Pollen analysis shows that indigenous palm trees
  were grown in the time of early settlers
• large areas given over to food production (upland
  farms)
• Food supply limited
• upland farms abandoned
• analysis shows large game birds disappeared
• Large fish and seal bones also disappeared (no
  trees, no canoes, no deep water fishing)
• Fuel supply limited
• carbon tested early fires were trees, later fires
  were grasses
• Erosion
• soil eroded from base of statues,
• Unrest
• In the last days statues of rival clans were torn
  down

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Reasons for collapse

• Cults formed and statues were built to worship
  the cults.
• Many trees were cut down in order to move the
  statues (log rolling compare to Stonehenge)
• Rats ate the seeds leaving the island without
  trees
• Boats slowly disappeared so people could no
  longer fish.
• The soil washed into the sea (tropical
  thunderstorms) because there were no trees ? no
  means to farm.