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Transcript for Nordic Sagas

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TEACHING GUIDES


Nordic Sagas: Island Life


The explosion of an underwater volcano 20 miles south of Iceland in November 1963 gave scientists a rare chance to observe life developing on a new part of the Earth, from the beginning. The island of Surtsey became a living laboratory for ecologists, biologists and others to watch as nature took up residence. Scientists have been careful to preserve this small island in the North Atlantic, and Frontiers was privileged to accompany scientists on a field trip.

Curriculum Links
Related Frontiers Shows and Activities
Activity 1: Birth of an Island
Activity 2: Invasion Tactics




CURRICULUM LINKS


BIOLOGY

evolution

CHEMISTRY


exothermic reactions
EARTH
SCIENCE


oceans, volcanoes
LIFE
SCIENCE


ecosystems, succession
SOCIAL
STUDIES


Iceland




RELATED FRONTIERS SHOW AND ACTIVITY

Science Italian Style (Show 503): Eruption!





ACTIVITY 1: BIRTH OF AN ISLAND

The creation of Surtsey from an undersea volcanic eruption has given scientists a unique natural laboratory where they can observe how life invades, colonizes and changes over time.

From the first signs of smoke, mistaken by a fisherman for a ship in trouble, Surtsey has been a focus of deep scientific interest. Surtsey is the result of a relatively shallow water volcano (about 130 meters below the surface) -- unlike the Hawaiian Islands, which formed from eruptions originating deep on the ocean floor. The eruptions that created Surtsey sent material out in horizontal blasts, causing the island to spread out. The final eruptions that formed Surtsey sealed the island with a layer of rock that protected it from washing away immediately.

OBJECTIVE
Model a shallow underwater volcano to see what type of island forms.

MATERIALS
  • hydrogen peroxide (household brand is fine)
  • yeast (dry or rapid-rising)
  • small glass jar with lid
  • gallon jar or fish bowl (deep enough to hold small glass jar but not too wide)
  • safety glasses
  • hammer and nail or other tool to punch holes in jar lid
  • notebook and pencil for observations
NOTE: Make sure yeast and hydrogen peroxide are fresh. The reaction will begin almost immediately when the yeast and peroxide are mixed. You may wish to place a small, clean rock in the bottom of the jar before mixing to prevent it from floating in the fish bowl.

PROCEDURE
  1. Pour enough water in the fish bowl so it will cover the small jar by two inches.

  2. Punch five to ten holes in the lid of the small jar.

  3. Pour about 150 ml (1/2 cup) of hydrogen peroxide into the small jar.

  4. Place about two teaspoons of yeast into the small jar, stir and cover quickly.

  5. Place the small glass jar, with lid on top, into the water on the bottom of the bowl.

  6. Observe how the "eruption" progresses. Draw the formation of the island at different intervals.
QUESTIONS
  1. What happens as the hot "lava" contacts the cool "seawater"?

  2. Examine the drawings of the "island" that forms when your volcano erupts. Can you identify different areas where life might begin to colonize? How might different forms of life get to these areas?
EXTENSIONS
  1. Iceland and Surtsey lie in an area of the North Atlantic Ocean with extreme winds, up to 200 m.p.h. What effects do weather and climate have on island formation? How might weather affect the long-term survival of Surtsey?

  2. What effect does modifying the model have on island formation? For example, what kind of island forms when the eruption occurs at a greater depth beneath the surface? What happens when the eruption occurs above the water line -- like those in Hawaii?

  3. Mixing hydrogen peroxide and yeast causes an exothermic chemical reaction. Explain.




ACTIVITY 2: INVASION TACTICS

Whether by water, wind or hitching a ride on other organisms, life found its way to Surtsey. Tough pioneer species were the first to establish a foothold. Plants, insects, birds and other organisms used a variety of devices to travel to a new land.

OBJECTIVE
Study different ways life can invade an island.

PART 1: PLANT INVASION
The first plant observed on Surtsey was the sea rocket, but the first flowering plant to really take hold was the sea sandwort. This plant's hardy seeds rode on ocean currents, surviving the extreme cold of the North Atlantic. Other seeds blew to the island or hitched a ride on (or in) birds. Collect various seeds where you live and determine their "preferred" mode of travel. If seeds are not available for collection, try a craft store for a variety of dried seeds. You can also use bird seed and packaged seeds for flowers and vegetables.

PROCEDURE
  1. Place samples of each seed in water to determine if they float. Leave them in the water for several days to determine which float the longest and therefore have a better chance to "find" land.

  2. Use a fan set on high, oriented to blow horizontally, to simulate the fierce winds of the North Atlantic. Drop seeds into the "wind" and record which seeds fly the farthest.

  3. Find a cat or dog that will cooperate and see which seeds stick to its coat and are carried away.

  4. Examine each seed under a magnifying glass or microscope to see if there are any obvious adaptations that favor one form of travel over another.
EXTENSIONS
  1. Does floating in water affect a seed's ability to grow? Design an experiment and explain your results.

  2. What effect do you think substituting salt water for fresh water would have on the seeds' floating? Design an experiment and explain your results.

  3. Some seeds get to Surtsey by traveling inside a bird to be excreted in bird droppings. Seeds that tend to travel this way are usually part of a berry or fruit. This is an example of mutualism. How do both organisms benefit from this relationship?

  4. Sea beans are seeds that drift to tropical islands, where they are often found on beaches. Some well-armored seeds can float for two or three years in the ocean. Would tropical seeds have a better chance at survival than seeds floating in the North Atlantic? Explain.
PART 2: BIRD INVASION
Wing size and shape determine which birds fly where. The first birds to make use of Surtsey were shorebirds like gulls with wings that take advantage of brisk winds found along the shore. The snow bunting, the first passerine (perching) bird to take up breeding residence, was most likely blown to the island. The snow bunting is a robin-sized bird with elliptical wings for slow, steady flight.

Compare and contrast the wings of long-distance soaring birds capable of dealing with high winds (gulls) with the smaller, short-distance birds (buntings) that can be blown off course by the wind.

QUESTIONS
  1. The shorelines of Surtsey were the first areas colonized by birds. Why do you think this was the case? Why do you think it took the birds a while to find the island?

  2. As you see on Frontiers, more than half of the species now on Surtsey owe their origins to birds. Why are the contributions of birds so effective to colonizing new land?

  3. Charles Darwin observed several species of finch on the Galapagos Islands and concluded they evolved from ancestors isolated from mainland populations. Would it be possible for new bird species to evolve in a similar manner on Surtsey? Why or why not?





 

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