Webquest: Iceberg Ahead!
Icebergs are enormous. They can be taller than the Statue of Liberty and as big as a small state. Normally, only a tiny part of an iceberg can be seen from the surface of the water. Thousands of these massive glacial chunks are formed each year and many are carried hundreds of miles by ocean currents until they gradually melt away.
The Titanic's tragic collision with an iceberg in 1912 shows just how dangerous icebergs can be. The Titanic was such a massive vessel that passengers barely felt the impact as the iceberg ripped a gaping hole in the bottom of ship. The Titanic sank on its maiden voyage, but the glacial ice that doomed the "unsinkable ship" may have been more than 15,000 years old! Now, satellites carefully track these colossal ice cubes and create detailed charts to warn navigators about their constantly shifting locations (for an example, see http://www.natice.noaa.gov/products/iceberg/).
Fast Facts
- While icebergs float in frigid saltwater oceans, they are actually made of freshwater.
- More than two-thirds of the Earth's freshwater exists as ice in the form of glaciers and ice caps.
- Each year, there are enough new icebergs formed in Antarctica to supply freshwater to the world's six billion inhabitants and every industry on our planet for four months.
- Antarctica and Greenland account for more than 98 percent of the world's ice-mass.
- Icebergs drift at a rate of about 0.4mph (0.7km/h). The speed at which icebergs move is affected by many things, including their size and shape, ocean currents, waves and wind.
WebQuest On-line Exercise
In this journey around the Web, we'll discover how icebergs are formed, where they come from, and how long they last...and that's
just the tip of the iceberg!
Click on the Web site(s) after each question to find your answer. Your teacher may also provide you with a HowStuffWorksheet to make things a bit easier.
- Where do icebergs come from? What does the term "calving" mean?
- Why do icebergs float?
- We've all heard the phrase "tip of the iceberg." On average, what percentage of an iceberg's mass is above the waterline?
- The Titanic struck an iceberg in "Iceberg Alley." Where is this?
- In March 2000, a new iceberg called B-15 broke off from the Ross Ice Shelf in Antarctica and became one of the largest icebergs in recorded history. What state does it compare to in size? How long will it take the Ross Ice Shelf to replace the ice?
- Why do icebergs "B-15" and "C-16" threaten a major colony of penguins?
- Ninety percent of the world's ice mass is found in Antarctica. What is the current weather at the South Pole? Do you know what season it is? (Hint: It's the opposite season from North America.)
- A 12,000- year-old ice shelf in Antarctica recently collapsed. What factors do scientists think may have contributed to its breakup?
- What is the farthest point south an iceberg will normally drift from Greenland? What is the farthest point south an Arctic iceberg has been recorded?
Extended Learning Activity
You're the captain of an ocean liner traveling from London to New York City. You must make certain your passengers don't suffer the same fate as those on the Titanic. Review the iceberg positions in
the chart below to determine which icebergs could pose a threat to your vessel.
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Iceberg Positions
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| Iceberg | Latitude | Longitude |
| 1 | 50.0 N | 45.5 W |
| 2 | 44.1 N | 46.1 W |
| 3 | 41.8 N | 47.8 W |
| 4 | 49.7 N | 48.0 W |
| 5 | 47.9 N | 49.7 W |
| 6 | 51.9 N | 38.5 W |
| 7 | 53.0 N | 43.5 W |
| 8 | 41.5 N | 54.5 W |
| 9 | 42.5 N | 57.5 W |
| 10 | 40.8 N | 57.6 W |
- Print out the map from this site to enter your data (hint: print the map using landscape mode): whale.wheelock.edu/whalenet-stuff/MAPSindex/images/NorthAtl7_5.jpg.
- Carefully plot each iceberg on the map by drawing a small circle. Then, write the iceberg's number inside the circle.
- Assume your ship enters the map at Latitude 42.0 N and Longitude 45.0 W. New York City is located at Latitude 40.5 N and Longitude 74.0 W.
- Draw a line showing the ship's path. Which icebergs should you be most concerned about? Also, using a capital "T," show where the Titanic hit the iceberg (Latitude 41.46N and Longitude 50.14W).
Here's a chart showing known locations of ship collisions with icebergs: researchers.imd.nrc.ca/~hillb/icedb/ice/bergs2_01e.html.
- Where are the greatest number of collisions occurring?
- How do the data on this chart compare with your data?
- What is the location of the northern-most collision?
- What is the location of the southern-most collision?
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