Jason P.
Chris C.
Class Portfolio
Mountains to Monsoons
In the unit Mountains to Monsoons we studied a certain interaction that occurs between the biosphere, the Lithosphere, and the Atmosphere. Basically, we learned that a monsoon is made possible by the interaction of water, land, and air. The monsoon that happens around the Himalayan mountains is a real life example of how mountains can create a monsoon. This exam brings to together all the information we learned in our mountains to monsoons and tested us on what we learned from the unit. Mountains to Monsoons Test The Indian continent collided with the Tibetan Plateau 45 million years ago.
We know this because of the information we gathered in the paleomagnetic Lab. In this
lab w discovered that India was once its own continent. We are able to locate the
original location by the magnetism and latitude. When a rock is originally formed,
it has iron in it that points to its magnetic north during that time. If we put
that rock into a magnetometer, we can discover which way the iron was pointing
during a certain time. This gives us the latitude of where India was located.
The older rocks can give us past locations and newer rocks and snow where India
has moved to. Also, the Micropaleontology lab gave us more information on the
movement of India. In this lab, tiny animals in the ocean became fossilized
when they died and fell to the ocean floor. When they are fossilized in the
sediment they become micro-fossils. Scientists use microscopes to study these
fossils and they are able to see changes in the fossils to see when the animal
was alive, some of these fossils have developed and some have become extinct.
By comparing the fossils to today's animals and previous fossils we are
able to date the surrounding sediment. By using the latitude from the
1st lab and the dates of the sediment, you can compare
them to show the movement of India. We see that India seems
to slow down about 45 million years ago because the latitude
stops advancing yet the date of the sediment still get younger. Also,
we know that when India was near the equator, warm water fossils were
placed on it and we can find traces of these deeper in core samples.
Now, with India in the North, cold water fossils are present. Before
India collided it had live fossils. When the animals died, they were
fossilized and we see them in the core samples as biogenous fossils.
After the collision, a lot of rocks were sent down in the earth so that a
layer of terragenous fossils formed over the biogenous layer, proving the
movement of India and the age by using the dated of when the terragenous
layers were formed in ore samples. When India collided with Asia, it was only pressed up against the continent
and nothing was happening. We know this because of the information we gathered in
Lab 2. This happened 45 million years ago. Then 18 million years ago India began
to slide under Asia because they were on a convergent plate boundary. India and
Asia are each on different plates, India was on the Indian plate, and Asia was on
the Eurasian plate. While India was sliding under Asia, Asia was pushed upwards
so that mountain building began, which we learned in Lab 3, the Sediment Lab.
Seven million years ago was when uplift began. This means that what once was
the Tibetan Plateau has transformed in to the Himalayan mountains over time,
and they are still growing today. As the plates continue to slide the mountains
continue to grow, and this has changed the face of these two continents forever.
The way we can date the fossils in order to find out how long ago India
collided with Asia is that material will fall down to the bottom of the Ocean
building layers of whatever material falls to the bottom. The materials will
move further and further down as time passes because of the opening on the
bottom which is spreading apart and then the clay on top compacts these materials
further down. This has to happen above the CCD level, which is 4,000 meters above
the Earth and below that layer the ocean becomes too acidic for materials to exist
and they dissolve. This is why we can find materials that should have dissolved so
far below the earth. The clay on top pressed against and protected it from the water,
which was learned from Lab 2 The formation of The Himalayan Mountains created changes n wind patterns. The warm
air over the land rises. As this air rises the cool air from the ocean is blown to the land.
The warm air condenses and cools because of the cold climate of the mountains. Now,
instead of moving to the ocean, the air stays above the land. The cool air from the
ocean continues to move over the land(sea breeze, high blows, low sucks). So, basically,
instead of dissipating, the warm air stays in the area. This creates a tighter loop
of convection. We learned this in lab 5. We learned how the change of wind patterns
cause monsoons. The wind causes up welling in the Arabian Sea. The deep water
brought to the surface is colder and richer in nutrients. The colder water organisms
flourish more during this time. This is how the wind affects the ocean. We learned
this in Lab 4. At the peak of the monsoon upwelling was also at its peak. In Lab
5 we learned the change in the wind pattern caused the monsoons. During the
monsoon period (this is during the summer) a steady sea breeze blows. The sun
evaporates water which is stored in the clouds. The clouds get blown from
the ocean over to the land. They can't pass through the high pressure system
( the hot air that's cooled and condensed). So, without anywhere to go, the
clouds release a massive amount of rain for a long period of time (6 months).
In conclusion, the formation of the Himalayan mountains create changes in the
wind patterns. The change in the wind patterns, in turn, changes the climate
(heavy rain) for about 6 months. After a monsoon there is a drought. The
climate change is very drastic.