Module IX

Earth's Fresh Water

Essential Question:
How are climate, terrestrial ice and Alaskan indigenous cultures all connected?

~Explain
Taking a look this week at the TD video, Earth's Cryosphere: Antarctica it explains that frozen fresh water is vital to our planet's climate. Terrestrial ice is the fresh water that is frozen on the land of our planet. This water represents a mere 2.8% of the total water on Earth! (USGS Water on Earth) Scientist from all over the world are currently using samples of ice, water, wood, mud and coral to determine the history of our climate. Nasa's Earth Observatory explains that, "Land area is larger and snow cover is more variable in the Northern Hemisphere than in the Southern Hemisphere." Residents of the rural communities in our state have noticed significant changes in their landscape. Permafrost is melting and causing the earth around it to move. This creates a risk for the animals that live there and the people and other animals that depend on the creatures that live within their cycle of life.

~Extend
The discussions that I have been in previously about global warming the comments have been that the current warming trend that we are seeing is just part of the ebb and flow of temperature. Scientists will tell us that climate does change over time, but that the changes are NOW happening quickly! They believe that greenhouses gases that are increasing are influencing the drastic climate change. The Nova video on TD Fastest Glacier explains that on Greenland, winter temperatures have risen 6 degrees. The warmer winter temperature allows for a longer melting period and therefore more of the glacier moves towards and into the sea. This allows more fresh water to dilute ocean water and can cause serious problems in the movement of water within our oceans. This process has a great effect on our planet's weather.



Antarctica has 65% of the world's fresh water. Scientist predict that if all of the glaciers on Antarctica were to melt, it could raise our sea level 240 feet! These figures would have us all living on the island of Atlantis! Our response to rising sea level should not be to train our students and family in the art of scuba diving, it is to educate them about strategies for reducing greenhouse gases.

~Evaluate
The TD video Earth System: Ice and Global Warming is an outstanding summary of global warming. Students could relate to the images as being local and it gives simple reasons why and how people are contributing to our planet's weather. I also enjoyed the TD video Melting Permafrost, because it gives perspective to the life cycle. Students will be able to see the pictures of the permafrost that is exposed and hear the reasons why a drastic change in it will impact the community that lives on top of it.

My grandfather grew up in Ruby in the early 1900s. He used to tell us stories about watching the last steam boat head up the river for the season. He said that it was a sad time because you knew that there would be no more contact with the rest of the "outside" world until spring. He said that the return of the boats in the spring was a cause for celebration. With the boat came fresh people, supplies, and news! Scientist have counted over 12,000 rivers in Alaska! Beyond the scientific importance of fresh water both liquid and solid there is a cultural importance to the communities that live near the fresh water ways. Changes in the climate and temperature can change the balance of life here and worldwide.

Images from Bing.com