6. If available, place news clippings and magazine accounts of major earthquakes on the bulletin board. (It would be helpful to keep a file of news and magazine accounts of major earthquakes for future class use).
7. Discussion: Is your part of India in the earthquake belt? Has your community experienced an earthquake? An earthquake tremor?
8. Research Report: Some buildings can withstand the effects of earthquakes better than others. How are they built? What other measures can be taken to minimize the effects of an earthquake?
VOLCANOES
When water enters the magma or liquid rock chamber it will turn to vapour and locates weak section like cracks to come out. If the crack opens out of the liquid rock to the surface, through which magma comes out, it is termed as a volcanic eruption.
When magma comes out it is called lava. The pipe through which magma comes out is called the vent. The mouth of the volcanic eruption is called a crater. Accumulation of materials like ashes, cinders or rock forms a mountain called a volcano. The common landform usually formed by volcanic eruptions is a plateau. Example The Deccan Plateau.
There are over 500 active volcanoes throughout the earth. Most of the earth's volcanoes are either extinct or dormant. Volcanoes come in all sizes and shapes: from small mounds to high mountains and from volcanic cones with gentle slopes to ones with steep slopes.
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1. Research Report: Some famous volcanoes: Etna, Vesuvius, , Fujiyama.
Where are these volcanoes located? Are they still active? How much damage have they caused?
2. Research Report: The "birth" of a modern volcano, PARICUTIN Mexico, February 20, 1943.
The literary-minded among your class might wish to dramatize the volcano's "birth" in the form of a playlet or on-the-spot radio report.
3. Research Report: What is volcanologist? (A scientist who studies volcanoes).
Include the kinds of research projects studied by a volcanologist: (origin of volcanic heat, how and where magma forms, utilization of volcanic heat to generate electric power, how the flow of lava can be regulated to save lives and property, how volcano eruptions can be predicted.)
4. Research Report: The economic importance of volcanoes.
Isostasy:
It is described as a gravitational balance between the land or continent and ocean. Continents are formed of lighter materials than water; hence they float on water masses. Mountains are higher landforms but they are formed from the sediments of the sea. When there is erosion of landforms pressure below the land becomes less. Simultaneously erosion deposition also takes place. Owing to this the molten materials get disturbed and start flowing (plastic flow). To maintain the balance the low-lying areas will emerge.
An analogy similar to this is the relationship between an iceberg and water. Floating ice remains about 1/4 above water and 3/4 below because it is less dense than sea water. Thus, in a similar fashion, the continents rise above the floors of the ocean basins because
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