MODULE III

How are landscapes formed and how, in turn, are cultures shaped by their landscapes?

~EXPLAIN ~
Historically geologists thought floods,earthquakes,and land bridges accounted for the current location of our continents. However Alfred Wegener through exhaustive research of similar coastlines, plant and animal fossils, and rock types between continents surmised that the earth was once one huge continent known as Pangaea. He attributed the continental movement to centrifugal force or sun/moon gravitational forces. After his death, geologists determined that this supercontinent broke apart and the continents shifted to their current location driven by convection currents within the mantle. This gave rise to the modern concept of plate tectonics. That the entire earth's crust, both continent and ocean floor, is composed of large plates that are moving to shape our landscape.

Landscapes are formed from the constant, however slight, movement of the lithosphere caused by tectonic plate movement. Weathering and erosion then act on these landscapes to keep them in a constant state of flux. There are three different types of boundaries where these major plates meet that determine what type of landscape will be formed from the movement.

Divergent boundaries create new crust where two plates move away from each other and cause a rift that is filled with magma. These are usually located at mid-oceanic ridges and produce a denser oceanic crust.

Convergent boundaries can create valleys, ridges, and mountain ranges (Himalayas) where two plates of continental crust crash into each other. Sometimes the denser oceanic crust meets a continental crust causing the oceanic crust to slide under or subduct.

Transform boundaries are where two plates rub together causing extreme tension that is released in the form of earthquakes.

For generations different Alaskan native tribes have had to adapt to their unique environment to maintain their subsistence lifestyle. Cultures have developed a dependency on the landscape to meet a plethora of needs as well as maintain their cultural identity. When the landscape changes through the seasons and over time, they must adapt their habits in order to ensure their very survival. Landscapes and seasons determine the availability of natural resources which in turn determine the use of these resources for the tribe's survival.

One example is the salmon run and how a multitude of issues (pollution, water quality. over fishing at the mouth of the river etc.) affect its productiveness. If the salmon run is low for a particular year they must share the meager catch with the entire village, Elders first, to ensure food through the winter season. If they want to ensure their grandchildren will be able to enjoy the same subsistence lifestyle they must be a part of the management of the resource to ensure they have salmon for future generations to enjoy.

~EXTEND~
I would use the videos that I found on Teacher's Domain to help my students (particularly the visual learners) to understand the concept of plate tectonics better. Second graders would enjoy the interactive video Mountain Maker, Earth Shaker and the video Rock Cycle Animation to explore the natural world around them. I would bring samples of rocks found in Alaska to round out the unit.
~EVALUATE~

It was very thought provoking learning about how an entire village upstream can be adversely affected by the decisions and habits of others at the mouth of the river. Until this course I didn't appreciate the real threat of loosing the salmon fishing way of life for future generations based on current procedures.

A subsistence way of life forces people to "become one with nature" and to appreciate its power, diversity and constant state of flux over time. The rich oral experiences that are being passed down by the Elders to ensure this way of life doesn't vanish before future generations can experience it is also very intriguing to study. Natural cycles connect the people to the land and reverence for the land protects the habitats for future generations. The native core values of interconnectedness, sharing and respect for Elders are sorely lacking in our technology driven, indoor lifestyle!
I was invited to an Elder's home to eat a supper of salmon and salmon berries they had harvested from their home village of Nulatto. I wish I had taken this course beforehand to have enlightened my appreciation of the experience even more!