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ChromaDepth
Section I: A Tour of Planet Earth
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India and the Himalayas
Description: This shows India and the Himalayan Mountains. India wasn’t always part of Asia. It was once an island south of where it is now. It migrated north and rammed into Asia.
Things to Notice:
- When India rammed into Asia, nearby parts of Asia buckled and formed the Himalayas.
- Mount Everest is in Nepal, in the southeast corner of the Himalayas.
- The part of India just south of the Himalayas is flat because many branches of the Ganges River crisscross there, eroding the land.
- All of that erosion has resulted in two very large underwater silt ramps, visible in the “armpits” of India on its west side. (Indus River fan)
and the east side (Ganges River fan). The huge amount of debris that has come out of the Himalayan Mountains has been dumped into the ocean in those
places, forming two of the largest underwater fans in the world. These are superb places to look for oil, much like the Mississippi delta, the Amazon delta, and the Niger delta.
- India is a very solid, and therefore relatively old, continent that has run into a very soft boundary with Asia, creating the enormous deformation of the Himalayan Mountains.
- As India goes down beneath Asia, its boundary, and therefore the shape of the Himalayas, is in the shape of an arc. This is like the arc you create when you push down on a partially inflated basketball.
- India is often called the “rigid indentor” like a big, frozen candy bar shoved into soft ice cream. The candy bar easily deforms the ice cream and forces it upward making the mountains. Major faults are formed
when this happens all around the candy bar, which means that this is a very dangerous area for earthquakes.
- India running into Asia is also often compared to hitting a watermelon with a sledge hammer -- the watermelon squirts out both sides. So faults going out both ways from India, through China and through places like
Turkmenistan and Armenia, are related to India running into Asia.
- Afghanistan is the loop of mountains on the west between the India plate and the Saudi Arabian plate. It is getting slammed from two sides, like the guardrail hit from two sides by colliding cars. The guardrail
doesn’t do well in this continuing collision---it clearly gets bent out of shape by the continuing deformation. Afghanistan is therefore a place with many earthquakes.
Go back to Section I here
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