A Later Post Than The "A Really Late Post"

Hello 05 ,

I’ve been looking through at the older posts of our classmates and commenting on them. Some of them were really great posts and helped me clarify doubts which I wasn’t able to ask Ms. Tang. Also, reading through those posts helped me revise what I had been learning during these exciting geography lessons. Yes, now I believe exciting is the very word for geography, especially more so when we have Ms. Tang teaching us. (:

I believe the core of the module lies in looking at everything as a whole and linking parts up to form a complete picture. We need to think in terms of systems that interconnect with one another. These systems help regulate the Earth and we must be very careful not to interfere and affect them, since this can upset the balance of nature and harm our dear Earth and in due time, ourselves. In fact, we should actively try to prevent global problems from happening and solve existing ones like pollution, global warming to save the planet that is home to us.

These lessons have helped me find out how nature functions, something which I had always wondered but was too lazy to find out. Also, I have learned that it is quite useless to memorize stuff like a parrot without actually understanding what they mean. Knowledge acquired by memorising will never last you for a long time, and understanding about nature is much more exciting and fun. ^_^

Dat Tran

Waterfall formation

hello everyone,

all of you have mentioned a lot about the course of the river but waterfall is still left out. So I will be writing on how a waterfall comes into existence and why do they disappear after many years.

Waterfall is an upper course landform of the river where flowing water suddenly drops over a steep region. They often start as rapids or a chain of smaller steps.

So what leads to the formation of a waterfall? Usually it happens where a hard rock lies next to a soft rock. As the river continues its journey over the hard rock, the softer rock below is eroded at a faster rate by the processes of abrasion and hydraulic action. This gives rise to a cave-like formation known as the plunge pool at the base of the waterfall.
As the erosion continues, the hard rock collapses in the plunge pool due to pressure. This further erodes the base of the waterfall by abrasion leaving behind a steep sided valley called gorge.

Although the charming waterfalls that are present today will prevail for a long time, but they will eventually disappear. The hard rock gets eroded and keeps falling into the plunge pool, this way the waterfall is actually moving backwards and after sometime there will be no waterfall. This is a very slow process similar to the speed at which it is formed.

-manish

Justa little contribution;

Hi guys, I don’t think I’ll do another recap of the hydrosphere/atmosphere modules, so yep this is a reflection plus a little something at the back!

I must say that I favored the Physical Geography modules the most among all the others, from the lithosphere to the atmosphere. Maybe it is because I’ve had some prior general knowledge with regards to this subject, from encyclopedias to internet sites. I haven’t found physical geography a chore to explore as to me it was a great way to satisfy my curiosity about the natural world surrounding us all. Though I have never actually witness a volcano erupt, nor have I been around long enough to witness the formation of a waterfall, but the fact that there is much, much more behind all these awesome works of mother nature spurs me on to learn more.

I have benefited quite a lot from these modules, and I’m sure the class did too. Probably just the nature of these lessons are key to keeping most of us (or at least me) awake. During these times all I had in mind was to learn more, unlike other subjects where I aimed to capture everything for the sake of passing exams. Say, if only we all had this attitude in every class! As for the various tests including the one in assessment week, I believe pure memorizing terms and processes or practicing default answers from worksheets won’t get anyone anywhere. We need to sit back and take a look at the big picture, understand the entire thing as whole - not individual components. With such the ‘story’ will begin to make sense and answering any question would hardly differ from extracting some excerpts from a book.

Going through these modules certainly taught us in greater detail about the lithosphere, hydrosphere and atmosphere. Though some might say these are useless bits of information that we won’t need, but I beg to differ. Such science responsible for creating our perfect little enclosure in the universe, wouldn’t it be a bit too epic to consider useless?

Isn’t it amazing how all the processes that we learnt, of haven’t come to know of, all fit in nicely in the world we know today? Without our Earth’s crust existing in many continental plates moving around, we’d be able to walk to America. Without precious water constantly renewing itself by the water cycle, it would be too polluted to support life. And with a slightly tweaked atmosphere, we’d be either cooked or frozen.

Okay now for something interesting that I came across in a book! Then I decided to look up more on it.

The pororoca. Can rivers flow backwards?

This may sound kind of impossible, because we know that the volume of water flowing along a river is so massive that it always goes downhill; in accordance to gravity, and that an unnaturally immense counter-force would be required to reverse its flow, something unheard of to many, I believe.

Well this does occur, between the months of February and March. To the mighty Amazon river. Because of its very gentle gradient along its middle and lower course (about 2mm drop every km), and its wide mouth, the largest river in the world is subject to the periodic influx of the tides of the Atlantic Ocean. When astronomically high ocean tides occur, they override the Amazon’s current, pushing inland and reversing the current for over 800km upstream. This phenomenon is called the pororoca, and highly benefits ships weighing tens of thousands of tons as it gives them a free ride upstream. The power of this inland surge generates a wave which slowly increases in height as the width of the channel shrinks, resulting in a miniature tsunami – or tidal wave – that can be over 10m high at the 360km mark.

Good luck to those near the banks.

Kay i'm done.

Aaron

A Really Late Post.

Hey guys,

It's nearing the end of the holidays now and yes... I'm putting up my reflective post about the subject (my only one) to add to the many others before mine.

I was quite interested in learning about physical geography at the beginning of the module as I have always been interested in learning how geographical formations like mountains and rivers were formed. I guess it's because I found it to be an easy subject to understand once I got past all the terms and memorizing. Basically I found out that many natural processes are just part of one huge system and that a small change in any one of the processes can affect the entire system. In my opinion, to do well in the module does not require one to do a lot of memorizing, just a general understanding of what was taught in class. However, I had quite a hard time to catch up with the rest of the class as the soccer nationals were on during the 2nd term and the matches were always held on the days that the lessons were on as well. However, I am quite satisfied with the effort I put into the module. This module has made me realize that we cannot take our world for granted. Also, I learnt that we humans are slowly destroying this planet as we know it and this has made me more motivated to conserve power and live a healthier, 'greener' life.

I guess that concludes my reflective post. It may not be as long as some of the others but it is an honest summary of my opinion of this module.

Chee Chung.

Reflections

Hello 05!

Instead of touching on content since there is already an abundance of information from our notes, I am going to blog on my reflections about the entire module.

Earlier on, I have never realised the importance and usefulness of understanding things instead of purely memorising them. As such, much time was wasted pouring through notes trying to memorise every bit of information I could before examinations and tests. However, through the many times we spent uncovering numerous ‘mysteries’ such as “How are seasons/deserts formed?” as well as hands on activities like visiting a ‘secret’ drainage basin in NJC and creating tiny clouds, I began to realise that I was employing the wrong study techniques. In fact, understanding things and knowing how to apply them is actually more useful than memorising them.

This module also led me to appreciate the way things are and how they work together to form a huge system. Previously, while I understood what global warming and climate change was, I did not know that there was actually something called the ‘planetary heat balance’ and how everything actually worked and affected each other. Furthermore, the notion of ‘how rivers/meanders/waterfalls are formed’ never once came into my mind despite the fact that I had seen them first-hand.

I have realised the importance of appreciating what we humans are given (earth, climate, etc). It has taught me invaluable information that I would not have been able to learn anywhere else, and geography, to me, is not that boring after all!

-Chang Jie

Hello my friends
So since the previous posts already covered the drainage basin, infiltration, the hydrological cycle, the water balance equation and hydrographs, then i guess i would cover the river channel processes.
First, we need to understand when we do get deposition then can we understand the river channel processes.
So, how do we get deposition?
The first way is when a river entering a lake or sea and the velocity of the water decreases, deposition will occur. Another way is when the example of the meander. In the inside of a meander, the velocity of the water would decrease and the friction that the water experience would increase and this will result in deposition. So just to summarize, deposition occurs wherever the speed of flow drops.


To summarize what Miss Tang taught us about the processes of erosion, just remember CASH.

C- Corrasion
when the river uses its load (the stuff that the water is carrying e.g. rock fragments) to constantly knock against the river channel's walls and beds and this will erode the river. Miss Tang would like to think it as the rocks fighting the river and the rocks would eventually win and cause some kind of gradient in the soil.
Take a look at this- http://www.geography.ndo.co.uk/animations6.htm

A- Attrition
when rocks knock against each other. This will result in the smoothing of the rocks and also make the rocks rounder and it will also break down the bigger rock fragments into smaller
pieces. Using miss Tang's words, it would be the rocks fighting each other.
Here's a link to help you understand better- http://www.geography.ndo.co.uk/animations3.htm

S- Solution (Corrosion)
When water in river reacts chemically with the minerals and other impurities and dissolve and result in a solution. Point to note- there is a difference between a suspension and a solution.
Suspension- Light particles carried by water http://www.geography.ndo.co.uk/animations7.htm
Solution- Transportation of dissolved loads
Please do get the difference right!
Actually they are all on the same website haha- http://www.geography.ndo.co.uk/animations5.htm

H- Hydraulic Action
Is when the sheer force of water weakens/loosens the cracks present in the soil of the river. Action of the flowing water that hits against the river banks and beds.
This will remove loose materials in the banks of meanders and also strong in rapids and waterfalls.

Okay that'll be all for my post. Its funny how something as small as a rock particle can cause all the difference in the huge river channel processes.

This is keewei kthx!

Summary post.

Hey guys this is ivan da blogmaster with the reflective post.

So, what did we learn this semester?

Is Geography just a study of graphs and definitions?

Is it just a classroom subject worth only mugging for mere credits?

NOOOO.

Geography is beautiful. It is the intimate understanding of how our beautiful planet works;how each cloud, each hill, each river came to be. We need geography to fully appreciate the wonders of nature.

Just take a look around you. Geography is everywhere. The air we breathe, the vast expense of sky over our heads, the rain that falls from the heavens.

If you think geography is merely a boring textbook subject, think again.