The Natural History of Martha

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The Natural History of Marthas Vineyard
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Questions to answer

• How old is the Vineyard?
• How did it form?
• How did it get the shape and unique features?
• What about the fauna and flora, and the variety
  of ecosystems here?
• How is the island changing (ecologically)?
• How have humans affected the island?
• What is the future of Marthas Vineyard?

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How old is Marthas Vineyard?
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Geologic Time

• Is Marthas Vineyard old?
• What is old?
• How old is the Earth?
• How old is the Solar System, and the Universe
  (since the Big Bang)?

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The Geologic Time Scale
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A better view?
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The Pleistocene Epoch

• Started about 1.8 million years before the
  present (ybp).
• About a third of the way into it, the Earths
  climate began to change. We do not know why.
• THE GREAT ICE AGE BEGAN.
• It is called the Pleistocene Ice Age.

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The Pleistocene Ice Age

• Started around 1,000,000 ybp.
• Consists of perhaps four or five stages or
  cycles.
• The climate slowly cooled, then slowly warmed,
  then cooled, then warmed . . .
• Stages of the Pleistocene Ice Age Nebraskan,
  Kansan, (Iowan), Illinoisan, and Wisconsinan.
• Wisconsinan - most recent (started about 100,000
  ybp, ended only recently).
• There is evidence everywhere.

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The Wisconsinan Stage

• Lasted about 100,000 years.
• It is the final stage of the Pleistocene Ice Age
  (or is it?)
• The best understood.
• The most evidence.

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The Great Ice Age!
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Views from the North Pole.
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Glaciation in North America during the
Wisconsinan Stage of the Pleistocene Ice Age
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Other Ice Ages

• There have been several other Ice Ages, besides
  the Pleistocene, during Earths long history.
• First one at least 2.3 BILLION ybp, others at 950
  million, 450 million, 250 million.
• The Earths climate has changed many many times.

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Effects of the Pleistocene Ice Age

• Sea level changes.
• Plants and animals (migrations, major mammal
  extinction).
• Humans!

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Sea level dropped as much as 300 feet at times of
peak glaciation! How did this change the
coastlines of the world?
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The fauna of the Pleistocene was very different
from today. Many mammals have since gone extinct.
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The most famous Pleistocene mammal had to be the
woolly mammoth. There were four different
species of mastadons and mammoths (elephants).
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Mammoth and mastadon fossils are numerous and
still commonly found. Some are even frozen with
skin, fur, and internal organs still intact.
Possible source of DNA?
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The extinct saber tooth tiger was a ferocious
predator.
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There also existed a seven foot long beaver in
North America. It is obviously now extinct.

• This a fossil of the tooth.

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And what about the human species?How were humans
affected by the Ice Age?
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Some believe that humans hunted the mammoth to
extinction.
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Summary

• The Pleistocene Ice Age appears to be over, or we
  are simply in a warm stage in between the
  Wisconsinan Stage and the next stage.
• Either way,these stages take thousands of years
  to develop, so dont hold your breath.
• Certainly, the Earth is currently getting warming
  (Global Warming), and it may be due to human
  pollution, speeding it up.
• Only time - geologic time - will tell.