Physical Geography :D

Regarding format of the comment block.

2009-06-03T23:50:00.002+08:00

I've changed the way the comment block appears in every entry because I think this format will be more convenient as you guys can refer back to the entry itself while commenting.

All the best.
Minh.

(Haha, jusk asking, can the changes made to the format of the blog be counted as 1 comment for me? :D).

Summary

2009-06-02T12:28:00.007+08:00

Time flies really fast doesn't it? Well, that's a good cause MR HEAH IS BACK!!!!!! :DDDDD

so basically here are the things we have learnt throughout the term

Key Learning Points

1) How different things interact and work together to form a system

2)Balance is essential in every system

e.g. Thermodynamic equilibrium

Sara's example: Carbon dioxide, too little and we will freeze to death, too much and we will have global warming.

Its ironic that we are messing up the very balance that is keeping us breathing

3) Structure and composition of the atmosphere

-Nitrogen: 78%

-Oxygen: 21%

-Carbon Dioxide: 0.03%

-Other gasses: 0.97%

4) Importance of the atmosphere

-Block out UV rays

-provides oxygen

-keeps the Earth warm

5) The classic "place shapes people, people shapes place",that we have been learning since last year. Let's name this Heah's law :D

e.g. eskimos adapting to live in the cold

6) Global warming

WE HAVE TO DO SOMETHING ABOUT THIS PEOPLE!!!

7) The different types of rain, how do they occur and when do they occur.

-Relief (contributes to the formation of deserts)

-Frontal

-convectional

(adiabatic cooling is involved in all of the above)

8) Climate and weather

These 2 can always be seen as how warm and how wet a place is and is also dependent on its latitude and longtitude.

9) How to read a climograph

Apart from reading from the graph, we would also have to interpret the data or else all those numbers would just be useless.

10) Seasons and its relevance to the tilt and shape of the Earth

(refer to Minh's post dated February 23rd, very detailed)

11) How winds move

-The 3 cells (Hadley, Farrell and Polar)

12) Deserts

To clear up a common misconception, deserts are not formed where it is very warm, but rather where it is extremely dry. This can be expained byt the direction of winds which carry the water vapour which ultimately results in percipitation. :D

-Formation can be explained by tricellular model or relief rain

13) Drainage basin

-What happens to percipitation (Infiltrate, throughflow, baseflow, interception, throughfall, stemflow etc)

14) Hydrographs

-How to read them

-Its use (to predict the chances of flooding and how authorities have to evacuate the people before it starts to flood, or before the situation worsens)

In this case, the lagtime is very important to determine how much time they have to evacuate

-The factors which affect the shape and height of the hydrograph (shape,size, geology, etc)

15) River processes

-Transportation (the different types of loads)

-Erosion

16) Braided channels and deltas

17) Meanders

caused by -Diff velocities at diff parts of river

- Helicodial flow

How it can result in an oxbow lake

LIFE SKILLS

BE CONCISE

NEVER MEMORISE, UNDERSTAND

BREAK DOWN QUESTIONS

ITS ABOUT THE QUESTION NOT THE ANSWER

Change in Blog Format by Minh.

2009-05-11T18:48:00.003+08:00

Hi everybody!!!
I've just changed the blog format so that hopefully it would be easier for all of you to edit your own post and make comment.
Best regards,
Minh.

2009-05-09T20:16:00.003+08:00

Hello. Today, we just did some revision and we were asked to read up on the water formations along the river such as waterfalls, meanders and oxbow lakes. So, I shall now try to revise for you what meanders are and teach you what oxbow lakes are.

Meanders

A meander is a bend in a river, normally at its middle or lower course where the channel is deeper and wider, which is caused by two things:
a) the difference in velocity between the inside and outside bend of the river
b) helicoidal flow

A. There is a difference in the velocity of water between the inside and outside bend of the river. Water flows faster on the outside bend of the river (because water is flung out of the bend as it curves through the outer bend, causing greater erosion, resulting in a deeper channel and thus, less friction). This is why the bank of the outer bend is steep (refer to picture).
It is opposite in the inner bend where the water is slow moving due to a shallower channel and more friction, causing deposition rather than erosion. This material deposited builds up and creates a slip-off slope (refer to picture).
Hence, because there is higher velocity at the outer bend, erosion happens and vice versa for the inner bend, creating this wondrous formation - MEANDERS!

B. Besides that, helicoidal flow, which is water flowing in a spiral, means that water does not flow straight, so there will be meanders.

Oxbow lakes

Following up from meanders, it is (so) obvious that as a meander gets more and more meandered, the difference in velocity will become even larger because the inner bend will have collected so much deposition that it is much shallower than the extremely eroded outer bend, so as a river is more and more meandered, it will cause it to become even MORE AND MORE MEANDERED! It is a kind of positive feedback thing….

So what happens when it gets so meandered that the river actually joins together again? You will get an oxbow lake! Look at the picture and you can see that as it gets super meandered, the neck of the straight paths is only separated by a little land. So, the water can just break through, leaving the meander out of the river. Soon, this oxbow lake will dry out because it won’t receive any of the river’s water and it will become a meander scar.

So, there. Now you know what oxbow lakes are. Thanks for reading this. You have just wasted 5 minutes of your life trying to understand me because all you had to do was watch this animation (http://www.cleo.net.uk/resources/displayframe.php?src=309/consultants_resources%2F_files%2Fmeander4.swf) which is everything I just said. :D

The end.

Done by WENG KIN.

Geography rocks! (get the pun? :D)

PS: You can also read http://geobytesgcse.blogspot.com/2006/11/middle-course-of-river-meanders-ox-bow.html

Braided Channels and Deltas

2009-05-05T20:03:00.006+08:00

Ok, this is my first blog entry and may be my last post also (unless we have 22 more lessons :D).
Today lesson, we've come up with two concepts: braiding and deltas. Now I'm going to do some recap for you guys.

1) Braiding:
- A braided channel is a river within which the stream is divided into smaller and interlacing channels by small islands called "bars". (the picture looks like a bunch of epidemal cells, really)
- These bars are sediments deposited by the river and are very firm (in Bangladesh, people make use of these islands to build house on) because when old sediments are removed, new ones will arrive and be deposited at the bars
- Causes of this braiding features:
+ The river banks are easily eroded (materials from the banks will form the bars)
+ The more abundant the sediments are, the bigger and more of bars will be formed
+ If the river's discharge changes, formation of bars also changes. If less discharge, the river's velocity as well as its ability to transport sediments decrease and vice versa.
+ It also depends on the gradient of the river, if it's steep, velocity of water is greater and hence less deposition occurs. If the water flows more slowly, materials are easily dropped along the way.

2) Deltas:
- When a very large amount of sediments is deposited at the river mouth, materials will be piled up and new lands are formed here. These lands are called "delta".
- The river then has to divide to smaller channels called "distributaries" to overcome these blocks
- There are two types of Delta: arcuate and bird's foot (why not bird's feet???) but since (Miss) Peixin didn't say anything about them so i'm not going to mention here.

Extra stuffs about Delta:

Introduce you guys to the largest Delta in Vietnam!!! We call it "Đồng bằng sông Cửu Long", as translating to English, it'd mean "Nine Dragons river delta":

This Delta is formed at the mouth of the Mekong River. As you can see in the picture, the river itself has divided into 9 (nine) (:D) distributaries, that's why it's called "Nine-dragons...". In this area, people rely heavily on agricuture due to the rich of alluvium brought by the river.

OK that should be it :) Before i end my entry and go mug Chem stuffs, i want to remind you of the contents tested in assessment paper:
+ Atmosphere: - Climates, seasons
- Climograph
- Heat balance (no need to remember all the numbers but if you want to challenge your brain, then go ahead :D)
- Rain formation (adiabetic coolings, movement of air, types of rains)
* No global warming stuffs
+ Hydrophere: - Hyrpgraph
- Drainage basin (not sure about this)
- River channels processes
- Formation of waterfall
- River's features.

OK done! Have fun! :)

Vu Ngoc Quang (aka CT rep :D) 5/5/2009

2009-04-26T11:12:00.004+08:00

Today (24/4) Ms Lin walked into class.

and basically covered some new content that was essential to the following lesson's discussion.

Upper Course	Middle Course	Lower Course
V-shaped Valley	Wider flatter valley	Wider flatter valley
Mass movements	Wider and deeper channel Alluvial(loose material like sand/sediments)	Wider and deeper channel Alluvial(loose material like sand/sediments)
Vertical erosion (Bedrock[hard rocks] channel)	Increased sinuosity	Floodplains and levees

THEN we went onto River Processes and sedimental transportation

Ways that sediments can be transported

1. Traction - heaviest material that rolls along river bed requires the most energy to carry

2. Saltation - Rocks bounce

3. Suspension - Small particles like salt/clay/sand that is carried with water through turbulent flow. The MAIN form of sediment transfer

4. Solution - Minerals dissolved

Processes of erosion

The excess kilojoules of a river is harnessed to erode, the process of picking up and removal of material.

	Corrasion/Abrasion	Hydraulic Action	Solution	Attrition
Targets	Bedrock	Cracks	Bedrock	Sediment load
Nature	Drilling/sand paper	Pressure	Chemical	Impact
Outcome	Vertical/lateral erosion	Collapsed bank		Smaller/rounder

Erosion of RIVER CHANNEL

Sandpaper - the sediment load rubs against load, in collision

Hydraulic Action - Water enters the holes/cracks, which results in increased pressure. The air bubbles burst after heavy compression

Attrition - High pressure just result in impaction, collision

There was this Velocity-Particle grain size(diameter) graph shown which shows the velocity needed to carry a certain coarse material. However, the values of the graph cannot be considered seriously because not all particles are round.

So after these mundane content we started looking at pictures! Such as deltas...meanders...etc. and apply our knowledge!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

taro

Friday 17th April 2009 =D

2009-04-18T00:00:00.012+08:00

Today we did a recap on River Processes:
1) Erosion
2) Transportation
3) Deposition

So basically, the river erodes the rocks or soil and transports it and then deposits it when there is not enough energy left to carry it. (details are in the previous post by DL =D )

So we went over to the concept of Energy!

What affects the energy of the river?
- Discharge, which is the amount of water
- Velocity, which is based on the gradient, the cross-section/channel shape, and friction)

Discharge is easy to understand. If the river has more water flowing, it has more energy =D

Gradient too, if the river is more sloped (say, a waterfall, then it has more energy)
This is due to gravity:

Remember this?

Oh the horror...

Now for Channel Shape.
If the channel is narrower, there will be less friction for the water because there is a greater wetted perimeter/ greater amount of water in contact with the perimeter, thus wetting it/ greater- oh i dunno what la...
(wikipedia puts it as 'the greater the wetted perimeter, so there =D )
Also, wetted perimeter = the cross-sectional area that is 'wet' (courtesy of wiki as well xD)

So a river channel like this

will have more friction than one like this

supposedly, but won't the additional water that figure 1 can hold make up for the increase in the wetted perimeter, thus having a canceling effect or something?

ANYWAY, lastly, we have friction =D
This changes with different types of rocks

Next, we split into groups to try and predict how velocity changes from source to mouth.
btw, the source is defined as the tributary that is furthest away from the mouth =D

My group said that it varies because the friction due to greater wetted perimeter cancels out with the greater amount of discharge, so it's mostly dependent on the gradient, which can change randomly =D

The correct answer, anyway, was that velocity increases downstream as the eroded rocks get smaller and rounder, sediment load decreases, so velocity increases downstream =D

KK so that's basically what we did for lesson xD with this final extra question:
Will a group of salmon travelling upstream to, let's say, Bread, affect the velocity of the river?
My answer: No! xD

Here's a diagram why:
oh look, a fish!
Fishie wags his tail...

Fishie moves forward, Pushing the water infront of it infront...

So now we have a swarm of salmon...

AND VIOLA!!! (i'm sure i spelt this wrongly)
THE ARROWS CANCEL EACH OTHER OUT!!!
you can see that there are the same number of front-arrows as back-arrows =D

And this concludes LLJ's FISH THEORY OF CONSTANT VELOCITY

(All pictures courtesy of ME and Macromedia Fireworks xD [seriously, you all should get this])

Current Geo Challenge Score: 1833 (T.T)

Oh well...

Until next time then...

Well-Wishes
LiangJie

MR HEAH GET WELL SOOOOON!!!!!!!!! <3 (hahas yes i just typed that)

07/04/09 Daryl Lee

2009-04-08T17:32:00.005+08:00

What a rainy day... Perfect for GEOGRAPHY =D. Today, Mr Faizal showed and explained to us what was happening at the 'garden' below our classroom.

So.. from what we have learnt from Mr Heah,

Firstly, there is interception, which is the trees, the grass and whatever that is obstructing adrop of water from falling down to earth to get absorbed by the soil.
SOMETHING LIKE...
YES! That is interception.

Then, there is infiltration, when water infiltrates in the soil.
When the soil reaches infiltration capacity, overland flow might result like we saw from the top of our classroom. Overland flow sometimes results in floods when it gets too serious. That is why vegetation plays an important role in preventing the soil from clumping together to increase infiltration capacity.
<---- OVERLAND FLOW There is also throughflow, which is water moving through the soil.
It is not as fast as overland flow, travelling at between 0.005 and 0.3m per hour.

After through flow, there is an even slower kind of flow, which is groundwater flow.
This happens when the underlying bedrock is permeable. Water will then slowly soak up the soil below and it will then flow through the small pores of rocks. This process is extremely slow. (takes a few THOUSAND YEARS)

Also, Mr Faizul also stated that some parts of the soil had clumped together as there is no vegetation on it and water is unable to infiltrate there. Therefore, we could see more overland flow at those parts of the 'garden' then at the parts with vegetation on it.
Human activity has also affected the hydrological cycle as water is unable to infiltrate through concrete and hence we could see (from the side of our classroom) lots of overland flow.

That's not all, we also read on the river channel processes which i will type about now =D.

Firstly, there are three river processes:
1) Transportation
2) Deposition
3) Erosion

1) Transportation
before we can talk about this, we have to know the kinds of load that a river carries
i) Dissolved load- Transport of chemicals in water (Solution)
ii) Suspended load- Sediments that is being carried by the flow of water (Suspension)
iii) Bedload- Material that is too heavey to be suspended in the water.
--> These are transported by rolling (traction) or bouncing (saltation)

so much sediments!

2) Deposition
Happens when velocity begins to fall, it has less energy and can no longer hold the load it is carrying.
Occurs when,
1) The load suddenly increases
2) Shallow waters
3) Low precipitation
4) When a river enters a sea or a lake (less velocity)
5) River overflow its bank hence the velocity outside the channel is reduced

3) Erosion
It is the picking up and removal of material.
3 types:
i) Corrasion- particles picked up by the river is rubbed along the river beds, wearing them away
ii) Hydraulic Action- occurs mostly at waterfalls and rapids. Air bubbles may burst in these areas sending out shockwaves which may increase erosion, this is called cavitation
iii) Solution- Dissolved CO2 from the air which is dissolved in the water may react with limestone and chalk, causing them to dissolve.

Lastly, there is attrition which is the particles that are being transported by a down-river crashing against one another causing them to become increasingly rounder and smaller in size.

ALRIGHT DONE! =D
GET WELL SOON MR HEAH =D

GET WELL SOON MR HEAH

2009-04-07T22:40:00.006+08:00

WE MISS YOU!!! PLEASE PLEASE PLEASE GET WEEL SOOON!!!!! YOU ARE THE AAWESOME-EST TEACHER EVER! LIKE SERIOUSLY. WE ARE ALL ROOTING FOR YOU TO GET BETTER. WE NEED YOU FOR GEOG!!!

love,

Nurul

HEY MR HEAH! GET WELL SOON!!! YOU ARE THE BEST TEACHER EVER, WITH YOUR ABILITY TO EXPLAIN CONCEPTS THOROUGHLY AND EFFICIENTLY! ABOVE ALL THAT, YOU'VE BEEN A REALLY FUN TEACHER TO HAVE! I FEEL THAT IT IS FAIR TO SAY THE WHOLE OF 01 REALLY ENJOYED YOUR LESSONS, OUTDOOR AND INDOOR, AND WE REALLY WISH TO HAVE YOU BACK FULLY RECOVERED!
GO MR HEAH!! HEEEEALLLL! o8IP01 WISHES YOU ALL THE BEST!!

-
GET WELL SOON MR HEAH! :D :D :D :D
we all missed you and your fun lessons!

GET WELL SOON MR HEAH!!!!=DD
[place your wishes here]

Jude Dominic

2009-04-04T15:52:00.005+08:00

Yesterday's lesson was mainly about hydrographs. A hydrograph shows the discharge of a river over a period of time. Storm hydrographs show the river's response to rainfall events. This is an example of a hydrograph:

The x-axis shows the precipitation as well as runoff discharge, which is measured in cumecs(cubic metres per second) and the y-axis shows time in hours. The green bars refer to the amount of rainfall. The curve shows the discharge through storm flow(throughflow, overland flow etc.), which is indicated by the blue part of the curve, and baseflow, which is indicated by the red part of the curve. The lag time is the time between the peak rainfall and peak discharge. The curve can vary due to different factors. If there is very heavy rain and the soil is saturated or frozen, there will be heavy overland flow and the curve will be very steep. However, if rain is light and there are a lot of trees and other vegetation( which results in more interception and obstructs overland flow), the curve will be less steep.

Hydrographs are highly useful to people managing drainage basins. The discharge rate of a river can sometimes be so high that the river floods its banks. Follow this link to see an animation of a flood(go to the bottom of the page and play the animation): http://www.geology.sdsu.edu/classes/geol351/hydrographs.htm. Human activities can also change a hydrograph. For example, there will be a generally low discharge rate in an area with much vegetation. However, if people clear the vegetation to gain land for other purposes, the discharge rate will become higher and flooding may occur.

We were asked to do the questions on page 231 of our notes as homework, so I may as well post up the answers here(although I'm not sure if they're correct. And I'm not going to give you the hydrographs here, because I can't draw hydrographs well on my pc).

2a) Lag time is the amount of time between peak rainfall and peak discharge.

2b) If lag time is short, a large amount of water will flow out in a short time, so there is a greater chance of flooding. If it is long, the water will drain out at a lower rate and there is a reduced risk of flooding.

3(i) a small drainage basin with very steep slopes: I won't give the graph but will describe it. The curve is a very steep one with a short lag time as the discharge rate is very high because of a steep slope.

3(ii) a linear shaped drainage basin: This graph has a gentle curve and long lag time. This is because the water discharges out slower due to the absence of a slope.

3(iii) a drainage basin that has recently been deforested: The curve is steep and the lag time is short. This is because there is less interception and overland flow because of the absence of trees.

3(iv) a long period of mainly light rain in summer: The curve is gentle and the lag time is long. This is because of less rain and because of more evaporation because of the summer sun. The tree canopy will also be at its highest at this time of year, so there is more interception.

3(v) a heavy rainstorm falling on thick snow in march: The curve is steep and the lag time is short. This is because the soil is frozen and so there is very heavy overland flow.

5. Hydrographs are useful to people for predicting floods and finding out how human activities like deforestation and urbanisation can affect the discharge rate of a drainage basin.

Water Balance

2009-04-01T18:19:00.003+08:00

The water balance lesson, was not really the best lesson as there was no Mr. Heah :'(... anyway, The lesson taught us that the water that comes from the environment MUST go somewhere and cannot just disappear. It was given by the equation P = (change in S) + E + runoff [cant remember the variables. trying my best to recall what was taught without the help from the notes :D.

So, P = precipitation, change in S = change in the storage amount in the soil, E = evapotranspiration which is known as evaporation + transpiration and finally runoff meaning the amount of water that was not absorbed by the soil being flowed away to a water body like a river or a lake.

So we were given some situations:
1) Cloud Seeding
2) Damming
3) Agriculture
4) Urbanization
5) Grazing

Basically, we just have to determine what factors were affected due to these 5 activities, resulting in a change in the constants. :D

Thats about it
Choo Wen Yi

2009-03-27T22:06:00.003+08:00

Hi everyone,

From today’s lesion, we were continuing to discuss about the drainage basin which is an essential part of hydrological cycle. To help us have a better understanding of it, we were brought downstairs behind TC block to see how the whole system looks like. By definition, a drainage basin is not only a river. Instead, it is the area that is drained by a main river and its tributaries. Those tributaries are always from higher altitude because water flows down due to the gravity by the earth. They contribute to the main river.

However, drainage basin is not only the water-flow. It refers to the area that is drained. Those areas are always covered by vegetation. Water does not flow very fast because of the existence of vegetation and soil.
Vegetation reduces the rate of the entire hydrological cycle because IT CAN STORE WATER. Hence less (Slower rate of the hydrological cycle is not the same as less water in the system) water will flow into the system. Different vegetation will result in different interception of water. Those huge rainforest will store more water than grass.

Vegetation also prevent the lost(loss) of soil. When soil is saturated, the excess water will bring the soil the river. It causes the lost of soil and an increasing level of river. Vegetation will store the excess water and hold the soil more tightened. Another factor that affects soil moisture is temperature. During summer, high sunlight density and higher temperature will let soil evaporate more water while water tends to remain during winter. (Are you sure?)

So far, we have discussed about the drainage basin and its river and how the vegetation zone store water. But why is water so important?

The main idea is that life needs a LIQUID MEDIUM to transporting the molecules that are necessary for its existence. Water is the main liquid in the earth.

How does water’s property help remain lives? The key is to understand the structure of water-------hydrogen bonding. Firstly, it becomes less dense as it freezes. It allows the ice float up to block the cold temperature from air keep freezing the water. Aquatic life hence can survive during cold weather. Secondly, it allows water to remain liquid state over a large range of temperature. That means it will not change its property of conducting molecule transporting easily(Liquids transport molecules far more effectively than Solids or Gases. Water stays as a liquid over a wide range of temperature). Thirdly, it makes water have high specific heat. It allows water remain in a stable range of temperature even absorbing a large amount of energy(Back to the question, water helps keep the body temperature constant). Furthermore, hydrogen bonding plays the role in reproducing and evolving life. It helps the 2 DNA strands bond together.

Nonetheless, water also other characters also helps maintaining life on Earth. It can dissolve materials (Chemicals? Compounds?) to assist in transporting molecules. The clouds also help block out harmful UV light. ( Ozone layer does, Clouds and dust only absorb heat)

Just a short revising,

Drainage basin contains 2 parts: River and its tributaries, the area drained.
The importance of vegetation zone: containing water (Should be reducing overlandflow by delaying the water flow and providing another pathway for water which is transpiration)
The importance of water: Hydrogen-bond (high specific heat(How do you know that H bond is responsible for it since H bond is not a strong bond?), large temperature range, DNA bonding) and other characters (perfect solvent, UV light blocker (Water never blocks UV light =.=), etc)

Comments made by Minh.
Lignum Rocks.

Cai Yida/27 March

Aditya

2009-03-26T17:21:00.005+08:00

Hi all,

On Tuesday we had our lesson near the fish pond where Mr. Heah taught us about the drainage basin. In the previous lessons we had about learnt the basic water cycle. Water evaporates from the water bodies, rises, expands and cools. Then the clouds get heavy and water droplets fall from sky as raindrops.

So, when a water droplet falls what can happen to it?--

1. So when the water droplet falls it reaches the ground surface and is soaked by the soil (Infiltration). The Infiltration capacity is the rate at which water soaks into the soil. If the amount of water received by the ground exceeds the capacity of the soil, this leads to collection of water on the surface. This is what we saw on the backside of staff room.

2. The water droplet can flow down the slope laterally. (throughflow)

3. The water droplets may flow laterally horizontally (baseflow)

4. It may fall on the trees and leaves (interception). Tree by itself acts like an inverted drainage system.

5. The water droplets that fall on the leaf may be evaporated or it may drop down from leaf (Through fall)

6. The water droplets may flow down the stem of the tree.(stemflow)

If we change the ground from soil to concrete then it can affects the drainage system and the water reaching the ground will decrease. This will severely affects the amount of groundwater and the water available to the plants.

Thank You.

Zhang Wanying

2009-03-06T23:31:00.007+08:00

Hello!
Today we started our lesson with a question: what did the rain come from last night? We were split into groups to discuss the question. So basically, the answer is, there are monsoon seasons happening twice each year in Singapore. The first one is the Northeast Monsoon which occurs from December to early March. The second is the Southeast Monsoon season which occurs from June to September. So now we are in the Northeast Monsoon. During the Northeast Monsoon, the place that receives the most amount of sunlight moves from the tropic of Capricorn to the equator. As a result, air of north part of the earth is cool and it sinks; air of south part of the earth is hot and it rises. The air moves up and down between tropic of cancer and tropic of Capricorn. Because of coriolis force which is due to earth’s rotation, air moves in this way:

The wind comes from northeast (so the wind is called ‘northeast wind’) of Singapore. As we can see on the map, the arrows indicate the direction of the wind. As a result, the wind brought the moisture of the South China Sea to Singapore. That’s why it was raining heavily last night.

From June to September is the Southeast Monsoon season. The place that receives the most amount of sunlight moves from the tropic of cancer to the equator. Hence air of north part of the earth is hot and the air of south part of the earth is cool, and air moves from south to the north. The air comes from Indian Ocean towards Singapore. Because of the unequal heating of land and sea, the air flows in the direction shown in the map below. However, there is an island with volcanoes called Sumatra blocking the air from Indian Ocean to Singapore. Hence, from June to September, Singapore is relatively dry. However, there is still convectional rain. It still get low amount of rainfall.

I guess that's all for today.

All the best for our assessment week. :)

Zhao Pei

2009-03-02T22:26:00.009+08:00

HELLO! HELLO! :)
So it is finally my turn to blog! Minh and Yida are absent both today. They are roommates of each other. I can not image what they were doing in their room while we were having Geo lessons...
Haha. Sorry for being so random. Today we talked a lot about the SEASONS and the DESERT. I think Minh had talked a lot about the seasons in his previous blog. So I shall focus on desert today:)
We are in the DESERT now! If you look at the world map carefully, you will notice that most deserts do not distribute among the equator. Places at the equator receive more sunlight and radiation than other places in the world. But why deserts are not found in equator?
Before we answer that question, we shall focus on the following two questions: "how does the air move around the earth? " and "how does gas transfer the heat? "
You can draw a diagram to show how the air move around the earth. And this is our answer :D

HOWEVER, all of us forget that the world we live in is 3D! But never mind, the teacher said we grabbed the concept already! :)
We shall take notice that warm air does not transfer forever, it will sink/rise once it gets cool/warm.
So here is correct version:

It is the same with this diagram below:

And we shall not forget that the earth will rotate from the west to the east. Therefore:

(I think I drew too many diagrams today and I hope they are useful.)
Last Question: Why desert are not found in the equator?
-What define deserts? What made deserts? (Dry! Lack of water→desert!!! Desert depends on amount of precipitation, not heat. )
Because ,the air is cooled down and therefore the air sinks at the hemispheres. (Which means there is no adiabetic cooling and air there will never rise.) Therefore there is very little precipitation around those areas. That is why you can see clear blue sky in the desert in the day time. Because there is no cloud covering, the temperature of desert is very high in the day time(40̊ C-50̊ C) and id very low at night (around-10̊ C).
So, that is about it, I hope:)

Comments:

Just to add on, I believe that the global air circulation is also one of the reasons why we

experience a tropical climate at the equator. For the presence of precipitation, there has to be adiabatic cooling. If we observe the 3-cell model, we notice that the Hadley cell, fuelled by heat from the sun, gives rise to rising air from the equator. Consequently, precipitation is greatest around the equator and gives us our tropical climate.

Similarly, as precipitation is the least where air descends, deserts also occur at the poles where the cool air sinks. As there is no precipitation, this polar deserts experience little snow, yet due to their location on the Earth, they still experience the cold climate unique to the poles. Its kinda cool actually :)

Victoria

Jingyi

2009-02-28T23:34:00.006+08:00

Hello!

Friday’s geog lesson was basically just a continuation of the previous lesson. In the groups that we were split into, we had to attempt to answer either the question of why are there seasons or explain the distribution of the Earth’s climate.

We were given time to reorganize the points that we came up with in the previous lesson into a more coherent answer that we want to present to the class. After that was done, some of the groups were called upon to present their answers. One thing that I learnt from the presentation of the answers was that there was a need to be organized. Most of the answers to the questions that are asked in geog are already known to us, thus what differentiates the better answers from the rest is how well they are organized. Organizing the answer properly also helps us to ensure that the answer is logical and is answering the question.

For the question that asked to explain the distribution of the Earth’s climate, the explanations given by the various groups were sort of summarized on the whiteboard.
The climate is generally distributed along the latitudes, as can be seen from the horizontal bands along the Köppen-Geiger map. In general, as we move from the equator to the poles, it tends to get cooler. This is due to the spherical shape of the Earth. The spherical shape causes the radiation from the sun to be spread out unevenly across the Earth. At the equator, the radiation would be more intense as compared to the poles, where the radiation will be forced to spread out over a larger region. Thus, there will be a higher temperature around the equatorial regions. However, there are also abnormalities as the latitudes are not the only factor affecting the climate of the region. The altitude, for example, would be one of the other factors. As the altitude gets higher, the cooler the temperature gets. This is why the Andes mountain range, the Himalayan Mountain range and the Tibetan Plateau are of the polar climate, despite them not being at the poles.

I’m not sure why deserts have a higher temperature than the equatorial regions (since it is closer to the poles than the equator) so can someone please explain that part to me?

The next question was sort of left unfinished, because the different groups were sort of like attempting to simplify the definition of the word ‘seasons’ (although I seriously think that the explanation got much more complicated in the end).

I think that we should not memorize definitions without first understanding it because it would be quite pointless. Furthermore, memorizing will only make things more difficult for us. When we understand the terms/concepts, we will be able to explain them without having to memorize them, thus we will not need to spend hours trying to soak up all the info in the various notes and textbooks.

Well, that’s about all. Byebye! =D

Minh - 23th Feb - Distribution of Climate.

2009-02-23T14:41:00.016+08:00

Basically during today lesson, we had to try to answer the question: "Explain the distribution of the Earth's Climate".

As usual, we broke the question into smaller parts and asked questions about every single one first, rather than diving in an ocean of info without knowing what exactly that we need. I realised that even simple questions matter much. We all thought about how the climates are distributed without questioning what "Climate" and "distribution" themselves mean. Questioning and answering those simple things really help us simplify the problem. "Climate" actually refers to how wet and warm the place is, therefore factors affecting the distribution of Climate must be those that affect the temperature and the wetness of the place. Cool! The problem has been narrowed down!

Next, the class was divided into two sides as you all knew. I fell to the season variation side. Our objective is to study why there are seasons on Earth ( I'm feeling that our side is actually answering the temperature half of the question ). And now, using all the progress that my group has made today, I would explain for you why there are seasons on Earth.

Firstly, seasons refer to different periods of the year when the temperature of each period is generally different from each other. 4 seasons Spring, Summer, Autumn and Winter nicely fit in a cycle of one year. Summer refers to the period when the temperature is highest throughout the year, and Winter refers to the period when the temperature is lowest. Spring and Autumn are rather intermediate period between Summer and Winter so the temperature at those time is in between that of Winter and Summer. Another thing to take note is that Spring comes after Winter and before Summer; Autumn comes after Summer and before Winter. Sounds simple, right?

So basically we differentiate seasons based on the temperature. And, as we all know, the temperature of a place generally propotionates to the amount of Sunlight received by that place. Therefore, the Sun has to be somewhat responsible for the distribution of heat on Earth throughout the year.

However, after studying the causes of season variation on Earth, I figured out that the REVOLUTION of the earth around the Sun and the TILT of the earth actually play important roles in causing season variation. And now I will explain to you with a simplified version of the picture that you can find in the notes itself.

First I shall explain a little bit about the picture.

The fish-ball like thing is actually our Earth in different position around the sun, and you should know that the Earth takes 1 year to travel 1 round in its orbit around the Sun. Therefore, the position of the Earth at a point of time is the same as its position one year later. And you also know that the Earth TILTs at an angle of 23.5 degrees with respect to plane that contains its orbit around the Sun. The yellow colour represents the part of the Earth that receives sunlight and blue represents the part of the Earth which does not. The equator represented by the red line divides the Earth into two halves, called North and South HEMISPHEREs.

Okay, now we have enough info to explain season variation. Let's put them together. As you can see, when the Earth is in the right-most position, which corresponds to 21-22 December, you can see that the South Hemisphere (S) generally receive more light than the North Hemisphere (N). And considering the Earth's "free body diagram" in this position, there are much more interesting things that you can see.

In the "free body diagram", the two tiny violet dots represent the two points on Earth which are symmetrical about the equator. As the Earth rotates, the two dots move along the two green lines with the same speed. On the diagram, you all can see that the dot in the South Hemisphere spends more time (More than 12 hrs a day) in the yellow region which is daytime while the dot in the North Hemisphere spends more time (More than 12 hrs a day) in the blue region which is night time, therefore the temperature the South hemisphere is generally higher than that of the North hemisphere and reaches its peak. Therefore, It's summer in the South Hemisphere and Winter in the North Hemisphere.

As the Earth revolves around the Sun for one more quarter of a year, to the second position on 21-22 March, the difference between daylength and nightlength becomes smaller and smaller and finally equal to each other. The temperature is generally the same in the two hemispheres. Because the daylength in the South Hemisphere is generally shorter than previously, therefore the temperature drops with comparison to the 21-22 December point and becomes mild. Similarly, the North hemisphere generally becomes warmer. Hence, on 21-22 March, It's Spring in North hemisphere and Autumn in the South hemisphere.

From here, you can figure out the rest, right?

The 23.5 degrees tilt of the Earth is very important for season variation. If this tilt does not exist, there would not be any difference between daylength and nightlength throughout the year at any point on Earth, hence no seasons.

However, there are much more interesting things than the season variation alone. By shifting the green line along the direction perpendicular to the equator, we get another result that the places near the two poles would have greater difference between the duration of daytime and night time during Winter or Summer and people living around the equator do not have to worry so much about the variation of daylength and nightlength because they have 12hrs of daytime and 12hrs of night time throughout the year. This helps us explain why the temperature of places near the equator varies very slightly as they receive a consistent amount of sunlight throughout a year.

And for the places which is at 66.5 degrees or beyond, there is an interesting phenomenon that a 24 hours or longer daytime/ night time can occur. And at the two extremes, the people who live near the two poles have possibly experienced a period of 6 months with, or without the Sun. You can try to explain this fact using what I've told you previously in this entry. Haha. Doing Physical Geog is fun, right?!?

Basically that's what I've got so far. We've gone through what seasons are, the key factors that causes season variation and the mechanism behind season variation.

*************

After diving into the pages full of words, I realised that the best way to learn something is to try to visualize it!!! So actually I focus on the picture first and even redraw them all so that I can imagine what is happening. And it was actually very effective because it took me only 15 minutes to digest the content in 8-10 pages of the handout. And after you've understood the thing, try to rehearse everything by your own words. By doing so, you would construct a system where everything has its own place and its own roles, hence reduce the amount of work that your memory has to carry out. Moreover, after you put everything in a complete system, actually you would realise that there are many unnecessary things that you can ignore. One more time, you can minimize the amount of info that our limited memory has to store. Personally I think that's the most effective way to study for me.

------------

Yawn!!!

I Think I SHOULD and MUST go to bed now.

Tmr Training 6.35 a.m, horrible.

Save me, God.

And all the best, Chandel (kidding only why so serious?).

Post for 20 Feb lesson: The Climograph (Victoria Lim)

2009-02-21T10:56:00.002+08:00

Today’s lesson was a revisit on climographs. From the previous lesson, we assembled into our groups to work on various climographs and presented our answers.
We went through again, how to describe a climograph. Most importantly, we have 2 main areas to cover, how warm a place is and how wet.

For both areas, we have to mention the magnitude, which includes the highs and the lows, as well as the distribution – the range. I learnt that apart from merely plucking numbers from the climograph, and trying to impress with our knowledge of statistics, we must, most importantly, interpret the data. The description is what is the core of the answer is, and it helps to use a variety of vocabulary to describe them. From scorching temperatures to freezing colds, intense rainfalls, to droughts. Additionally, we must be able to conclude from all these information, the general pattern of the climograph, thus giving us a good idea of the climate in that region.

The general pattern of a climograph can tell us many things, for example if the area experiences seasons and from which we can approximately infer the location of the area if we have to. In general, I noticed that climographs of regions in the northern hemisphere generally came in the shape of an ‘n’ (the temperature part at least), while countries in the south such as Santiago and McMurdo Station had climographs in a ‘U’.

This is because the northern hemisphere such as US and Russia experiences winter in the Jan/Dec period, with summer in mid-year, hence temperatures follow the n shape with approximately the highest temperatures in Jun. On the other hand, temperatures in the southern hemisphere experience the seasons in the opposite pattern as the north, having temperatures dipping lowest in winters in mid-year, hence giving rise to the U shape. Personally, I find this rather useful as it makes sense and indeed does help me recognise the general patterns. To add on, equatorial countries usually have rather stable temperatures, so their climographs will be rather flat, so called.

Something else which was brought up in class was that in certain countries, the pattern of rainfall followed the trend of temperatures. I’m guessing this is due to higher temperatures resulting in more evaporation leading to higher rainfall. But again, I suppose this does depend on many other factors such as the winds as well as location, so this trend might not hold true all countries.

One last thing I learnt from class today was to be careful not to mention things that cannot be explicitly inferred from the climograph. For example wind patterns cannot be seen from the average climograph and mentioning it in one’s answer will be almost suicidal. So, as the rule of the thumb, just work on whatever’s given in the question.

I guess that’s all :)

Victoria Lim

Hazel Goh

2009-02-18T21:36:00.003+08:00

So here's my post for Monday's geog lesson. :)

We talked a lot today about the climate and weather. We always want to know if it's wet or warm in a particular area. There are many ways to describe how wet or how warm a place is! Take for example, descriptions of warmth are, hot, cold, freezing etc. And the descriptions for wet are very wet, damp, mild etc. To add on, how wet a place is depends on the amount of rainfall and the precipitation in that particular area. Snow is not a type of rainfall, but it is a type of precipitation.

Then we watched a video! Bill Nye the science guy. It was a really funny but detailed video! :) It talked about the Earth having many different climates, and covered mostly by water. Different kinds of living things have found their way to adapt to the surrounding climates. Mountains have a big effect on climate, and can divide areas into two different climates, one side warm, and the other side wet.

After that, we learnt about the climograph! :) We were grouped into groups of 2/3s, and then made to evaluate the climographs. When we are doing climographs, we have to always read the title first! So that we would know where the location is. We also have to pay attention to the units, as the units are not standard across the countries. A climograph is a measure of the temperature/precipitation for the year in a particular location, measuring how warm/wet is the area. When evaluating the climographs, we have to look out for the magnitude and the distribution of the temperature and weather. The distribution includes the range (is there any fluctuations?) and the seasons (when is it warm/cool? How many seasons?). We have to describe the general pattern of a climograph via the temperature and precipitation!

When describing a climograph, we have to check out for

What are the general patterns?
Any special abnormalities? (Eg, suddenly going out of pattern)
Is it hot/cold?
Are there any seasons?
When is it wet, mild or dry?

AND, we have to be concise! Write as little as possible, and don't be too naggy and long winded! So here's an example of a climograph! :)

For the last part of the lesson, we looked at the latitudes and longtitudes of the world map! :D Climate is affected by location, which is the longtitude! And the world map is sorted out by climates and temperatures by looking at the different coloured areas.

So that's what we covered in on Monday! :) It was really enlighting, watching the video of Bill Nye. It was rather funny, and it showed us how to learn geography in a less boring way! Plus, learning to read the climograph was something new and rather interesting!

Eugenie Foo

2009-02-13T22:25:00.006+08:00

HELLOHELLO! :D
Today we had a long lesson full of information! So everybody, here it goes!

We did alot of things today and it includes the cloud-making experiment and learning the different types of rain. Firstly, the coke bottles! Before we started on the experiment, Mr Heah revised water cycle, also known as the hydrological cycle, and he revealed that we would be "making clouds" inside the coke bottles. Mr Heah gathered us around the teacher's table and he demostrated "making clouds". I'm sure everyone was amazed, and so was I! It was cool, to see clouds appear and disappear before our eyes. For the experiment, we needed a 1.5 litre coke bottle, and a little bit of water in the bottle. All we had to do was to extinguish a matchstick, trap the smoke from the matchstick in the bottle and cap the bottle up. Then, we had to squeeze the bottle and release it continuously. While squeezing and releasing the bottle, we see a phenomonen! x) We notice that when squeezing the bottle, the bottle is clear inside. However, when releasing the bottle, the inside of the bottle turns cloudy! Seeing this, we have just "made clouds"!

After the experiment, Mr Heah wrote two questions on the board,
1. Why is there a need to squeeze the bottle?
2. Why is the smoke needed?

1. Firstly, how do clouds form? Water vapour must become water droplets in order to form clouds. When we squeeze the bottle, the volume of the bottle becomes smaller, and there is a higher pressure in the bottle, and the temperature is high, and water remains as water vapour. When we release the bottle, the volume of the bottle becomes larger, and the pressure becomes lower, the temperature is low, and water droplets form! Therefore we squeeze the bottle to allow the pressure to change and cause water droplets to form as described above.

2. Now why is the smoke needed? Water droplets are really really small and therefore they only collide and bounce off. To make water droplets coalesce into a visible cloud, there is a need for a surface. And in the case of the experiment, aerosols (eg. smoke) serve as a condensation nuclei, which allow water droplets to coalesce into a cloud, therefore smoke is needed.

(:
Now, the different types of rain! There's 3 types, namely the relief rain, the frontal rain, and convectional rain. We were separated into 6 groups and were given 5 minutes to explain the various types of rain. This is what we learnt about the 3 types of rain:

1. Relief rain.
As the name suggests, this got to do with the relief of a mountain. As moisture-laden air approaches the mountain ranges, the relief of the mountain forces air to rise, and adiabatic cooling (air forced to rise, expand and condense, and water droplets form) occurs, and clouds form, and eventually, rain falls. The unique thing about relief rain is that all rain would only fall on the leeward side of the mountain. Why? At the windward side of the mountain, there is less moisture, and air sinks. As the air gets warmer, condensation no longer occur, and no clouds would be form, thus no rain.

2. Frontal rain.
As warm air meet cold air OR as cold air meet warm air, they do not mix. Instead, the denser cold air would force warm air to rise, and adiabatic cooling occurs, and clouds form, and eventually, rain falls. The unique thing about frontal rain is that this type of rain can only be found at temperate regions.

3. Convectional rain.
Heat from the sun heats up the ground and ocean, causes the air to get warmer (lower density) and rise, adiabatic cooling occurs, and clouds form, and eventually, rain falls. The unique thing about convectional rain is that it only happens at tropics and equatorial regions, and it would only occur in the day time, from afternoon to evening.

Yay, that marks the end of the lesson! It was an enriching lesson, and I never knew there was different types of rain! I have learnt how to "make clouds". I have also learnt what happens before it rains, and most importantly, I have learnt to use the correct terms in replacement of the layman terms, such as adiabatic cooling, coalesce, aerosols! Till next time, haha. :D

Comments: (here, name at bottom)
The most important thing to take note is the process how the air is forced to rise up. And the thing following it is just adiabetic cooling, clouds form and rain. The names of the types of rain also suggest what forces the air to rise. RELIEF of the mountain, hot air rises at its FRONT(AL) with cool air, and hot air rises up simply because of CONVECTIONAL air flow <- Shorter and easier to memorise. ( by Minh ).

Charmaine Khoo

2009-02-10T22:54:00.003+08:00

Reflections for Monday 9th February Geography lesson

I’m really sorry for the delay in submitting this reflection, I was not feeling well last night (went to the doctor's) so I did not have time to post. Here’s my reflection:

During today’s geography lesson, we watched the video “An Inconvenient Truth” by Al Gore. The main gist of it revolves round the topic of the increase of carbon dioxide in our atmosphere leading to global warming leading to adverse effects on Earth. I really enjoyed watching the video; its visual aids (such as graphs) helped to bring the message across very effectively.

The atmosphere is very vulnerable, very thin, and we humans are absolutely capable of changing its composition. As shown in various graphs in the video, the level of carbon dioxide produced into the air and temperature of earth are constantly rising and have risen significantly much faster over the last 10 years.

Glaciers are melting at a rate faster than anyone can imagine now, which brings detrimental effects such as the polar bears having to swim miles to find ice as depicted in the video and ocean waters absorbing the sun’s rays faster than before. This is indeed very worrying. It is good that we are exposed to such a phenomenon of the Earth. While we are cooped up at home in Singapore, we do not know what takes place in other places of the world such as the North and South Poles, where gigantic chunks of ice are melting away each day. How can we just watch our Earth fall into the hands of global warming like that and not do anything? What can we do to reduce the amount of carbon dioxide being released into the air?

I remember Al Gore talking about the carbon dioxide level in history, for as long as it was recorded. Earth experienced 7 ice ages, 650,000 years recorded and the carbon dioxide level has never exceeded 300 million parts (that’s how it was measured). Today’s carbon dioxide level has hit way, way above any record in history. As my eyes traced the line extending upwards, I was shocked at how sharp the gradient of this line is. The carbon dioxide level is increasing at too fast a rate for us! We have to do something drastic about this before all the remaining ice melts during summertime in 30-50 years.

He claims that there are 3 reasons for the possible collision of the world in future. The first is increase in population over generations, which put pressure on the supply of food, water and other resources as these have to be increased to meet the demands. Secondly, old habits + new technology = dramatically altered changes. Lastly, it is the sudden jolt to be aware of danger, as illustrated by the frog humping out of hot water. Do not wait till tomorrow to start making attempts to save the Earth, our home. We may not directly feel the effects of it now and thus not care much. However, we have seen the truth for ourselves in the video. Many countries/ states are drowning because of the excessive melting of ice into water around it. We have to start making the conscious effort now.

When the Earth’s overall heat gain is greater than its' heat loss, as being experienced now, what will happen? This leads to the question posted to us: To what extent should we be concerned about carbon dioxide emissions?

Comments: (here, name at bottom)

Chandel Tan

2009-02-06T22:40:00.001+08:00

Hello people:)

so it's finally my turn to blog about my geog reflections. it's kind of pressurising seeing how the previous 3 people all had uber long blog posts. HAHA. i shall try to make it long. and well, easy to digest. ok. so here goes:

today, we talked about THERMODYNAMIC EQUILIBRIUM, meaning that whatever heat gained from the sun to the earth will be the same amount as whatever heat lost.

we also had this really really short discussion on how heat transfer is made up of 3 mediums - conduction, convection and radiation. yes yes, i know we've already learnt that in sec 2.

Also, we touched on the electromagnetic spectrum, a 'bar' made up of the colours of the rainbow. so how do you actually intepret the electromagnetic spectrum? well, the lower the energy rays, the longer the wavelength on the spectrum. and as you all know, the coulours of the rainbow are in this order: RED, ORANGE, YELLOW, GREEN, BLUE, INDIGO, VIOLET.. yes.. so any wavelengths longer that the RED coloured part will be hereby known as INFRARED RAYS. (like how phones used to have infrared.. but i think these phones are pretty outdated already) and.. wavelengths shorter than the VIOLET coloured part are known as ULTRAVIOLET RAYS..

just for your information, heat gained from the sun is know as short wave radiation (which also symbolises a gain in heat on earth's surface). and heat produced from the earth is also called long wave radiation.. (meaning that heat is lost from earth)

apart from these facts, we also learnt to draw the diagram to depict the global shortwave radiation cascade. although it was pretty confusing in the beginning, we soon learnt the method of drawing the diagrams. the trick, however, is simply to read the instructions step by step. Personally, i feel that this simple method does wonders when one is truly clueless and confused as you are taken to approach the problem a step at a time. for example, in math, you don't usually go straight into the final statement and come up with the answer. you analyse it, then you try to find the right formula or something. then you solve. haha. yes.. it's the same thing for drawing of such diagrams.

we also did some group work during the lesson today, since we were made to come up with a diagram as a group. so we had some interaction with our classmates during geog lesson today. I have to say that many brains put together far surpasses a sole opinion since i not only clarified my doubts of the diagram's concept with daryl, but also managed to see how the diagram should more or less look like, since each of us contributed in one way or another during the illustrating of the diagram. Should I have tried to attempt it all by myself, I would not have cleared the question in my head, and might not even have figured out how the diagram should have been drawn.

In a nutshell, within today's 1 hour period, I not only acquired new knowledge, but also realised the importance of going a step at a time to acheive utmost success, and also how crucial it is to work as a team. I learnt a lot indeed.

Comments: (here, name at bottom)

Sara Chan

2009-02-02T17:59:00.000+08:00

The entire world operates as a system, and in order to maintain this system, regulatory forces are required to maintain balance. This may sound obvious, and scarcely in need of being repeated, but I feel that we do not quite register the significance of this. This balance is essential, it plays a crucial role in our continued existence (just like the atmosphere). Our lives, our future, our very existence is dependent on this balance. How ironical it is that we, as human beings dependent on this delicate balance are doing our utmost to upset this balance, an act which, should we succeed, can ultimately end only in the annihilation of ourselves.

When watching the video we saw in class today, the first thing that came to my mind was that our earth is beautiful. Isn't it amazing how the simple presence of the atmosphere has transformed the once (theoretically) barren planet into the gorgeous paradise we see around us today? (Or the paradise we would see if we didn't live in the concrete jungle of Singapore.) What a wonderful job the stromatolites (was that spelt correctly? stromatolites are the first life forms on earth, bacteria, the first to photosynthesize and produce that incredible life giving gas: oxygen) did of turning that "witches brew" of noxious fumes into the vibrant, life-supporting world of today.

The Earth is simply perfect for human survival, or perhaps I should say was. The composition of air for example, 21% oxygen, 78% nitrogen, 0.03% carbon dioxide and 0.97% sundry other gases, is completely ideal for human habitation. Too much oxygen would lead to the horrible anguish of lung damage as oxygen is a highly reactive element, while too would result in a slow suffocating death. The key then is balance: neither too much nor too little. Take carbon dioxide, along with other greenhouse gases as another example. Too little and we would freeze to death, but any more would lead to global warming. As we saw in the video today, global warming sets off a chain of other events. Apart from the obvious rise in temperatures across the globe, and the subsequent melting of the ice around the world, the rise in ocean levels and all the other problems brought on by global warming, there is also the melting of the permafrost in Siberia, releasing copious amounts of methane into the atmosphere. As an extremely potent greenhouse gas, the drastic increase in methane would lead to a great rise in global warming: a downward spiraling cycle where more global warming causes the release of more methane which in turn causes a rise in global warming and so on. How quickly things spiral out of control once we tip the balance! This balance we depend on is indeed delicate. Delicate and precious.

Another thing we learnt to day was how to analyze questions, a skill that will surely be useful, not only in Geography, but also in English, Chinese, MI, and possibly all of our other subjects as well. Breaking down the question does indeed help you to understand exactly what the question is asking for, and, consequently, makes it a lot easier to answer.

The last thing we covered today would be the carbon cycle, in which we once again made use of the nifty method of mind-mapping. Another thing that proves how perfectly the world is for survival: the way the carbon circulates. And another example of how humans are demolishing the earth through deforestation and whatnot. It may take some time to get used to mind mapping as opposed to memorizing all those facts and regurgitating them when the exams loom over us, but I'm sure as time goes on we will find it much easier. Not to mention we would probably die if we attempted to memorize everything we're learning for Geography.

Comments: (place here first, insert name at the bottom)

Geraldine Boh

2009-01-30T20:32:00.000+08:00

Reflection for 30/1/2009 Geography Lesson

The atmosphere is essential for life. It blocks out harmful UV rays from the sun, burns out meteorites, provide oxygen, and keeps the earth warm. And yet, it occasionally destroys life. Most weather occurs in the troposphere, and the effect of some weather condition can be fatal, such as hurricanes, tornadoes, cyclones, floods, which kills many in its path. How ironic. The atmosphere supports and yet destroys life. The atmosphere can be deadly, and yet, there are its beautiful moments, as we saw on the video today, the auroras and waveclouds. I suppose this is life. Nothing is certain or perfect.
Our atmosphere is akin to a giant 'ocean' , shaping our landforms, our country, and our people subsequently. It amazes me how everything is connected, not only within the atmospheric system, but also eventually, with other factors outside of it. Although this was not exactly touched upon during geography lesson, inspiration was brought forth by the term 'systems' that were mentioned so very often, and it dawned upon me sometime today.
Its like, within the atmosphere, the weather will occur in the troposphere, will shape the land through wind or water erosion, and subsequently the shape of the land will affect whether people can survive in that land area, and then how the people will live there, while at the same time the other parts of the atmosphere ensure that we have sufficient heat, oxygen, and carbon dioxide for plants to photosynthesise, and for us to have food to eat.
For example, the weather and temperature of the earth is distributed in such a way that it is cold and snows in antartica, but not cold enough such that life is impossible. The people who live near the poles (eskimos i think) are then shaped by our weather and distribution of heat (both are systems), they fish for food, adapt in the cold, wear thick coats, and because of the weather, they even have a language that is mostly revolved around how they live. The weather affects the land(systems are involved here), which affects the people living there, and should they use aerosols or contribute to the greenhouse effect (another system) , would affect the weather again.
It seems like the entire atmosphere, the entire earth, revolves around us humans. Or is it rather that we self centered creatures percieve them as revolving around us? The whole system is just so intricately designed, and they just fit so nicely together, large and interconnected, that sometimes its hard to tell which factor influences which exactly.
Everything belongs to a system, which in turn is interconnected to other systems in some way or another, which makes up our earth. The beauty of systems, indeed.

Comments: (add comments here first with your names at the bottom)

Audie

2009-01-20T01:22:00.004+08:00

I think the most important thing that was taught in class today was understanding how things work together as a system - the interactions and the roles each of them play. In doing so, we may find it easier to not just recall information, but to see the big picture and learn to truly evaluate and appreciate it.

It occured to me that in the area of Physical Geography alone, there are many different processes and cycles involved - the water cycle, the carbon cycle, so on and so forth. What I would usually do is to go online and google for information and then read all the lengthy articles that come my way, not truly understanding the links involved and why exactly things work the way they do. It is more often than not just a step 1, step 2, step 3 thing, memorised word-for-word. Concepts are not grasped and application then becomes an issue.

E.g. What is geography in the first place? Is geography a study of all these processes and cycles and how they are linked to human life? What is life? Do we understand these concepts?

In discussing the question: 'why is oxygen essential for life?' we covered the special characteristics of oxygen and how they were linked to human life. One thing that was brought up is that oxygen is extremely reactive, capable of giving rise to combustion and explosions, such as in the case of Apollo 1, but more importantly, to answer this question, it can combine with iron found in our red blood cells, and thus allows us to have oxygen to respire and live.

In fact, oxygen is a gas so crucial for the existence of not just humans, but all different forms of living organisms that it must be maintained as it is right now - the composition of air cannot be altered for otherwise, there will be drastic and severe consequences. All ecosystems will be dramatically affected and the world will cease to exist as we know it.

This brings to mind how the systems in the world are interlinked. Systems do not exist in isolation. In fact, the Earth does not exist in isolation, extending far beyond human observation, leaving an endless trail. There is an added dimension, with these interdependent systems, linked not just to understanding of physical landforms but even in direct/indirect relationships to politics (e.g. global warming), sociology and so on. Sounds ridiculous, but Geography indeed is a mass bank of knowledge summed up. Its relations may be so intricate that it goes beyond even human capabilities to fully grasp and understand.

But that is the subtle irony - it is a threat to survival and there is an urgent need to expand our knowledge on geography, yet it seems almost impossible for a human to grasp it in entirety. This pursuit may not always suffice, and it goes far beyond simply sitting in class and memorising information in notes and booklets.

Life and death coexist as polar opposites and even in this case, what seems so boring and irrelevant like understanding rocks and volcanoes could determine if lives are going to be saved, most relevant in nature. Nature and the man-made coexist as well and understanding these wide and expanded relationships are equally crucial. There is indeed no end, but that is what retains interest and wonder.

We also discussed in general, the structure and composition of the atmosphere, including important components such as nitrogen and carbon dioxide, which serves as a basis for food chains (required in photosynthesis for the formation of glucose).

These are minute details that act as a foundation, essential to build up an understanding. Nature can be seen to exist in the most subtle manners, almost non-existent like oxygen, but yet could be so complicated intrinsically.

We were also taught that in order to answer essay questions, one main thing we have to remember is that we have to firstly understand what the question requires us to do. After we get that right, our burden is very much reduced because it will take a lot less time to get our essays done without having to regurgitate and spill large amounts of information that is completely unrelated, or at least, vaguely linked to what the question is asking for.

It is insufficient to simply memorise information from books. Rather, what we should and must do is to understand the concepts, the trends and big ideas that these pieces of information indicate and hint towards.

In conclusion, three things have been learnt today:
1) The importance of understanding concepts and seeing how things work as a system
2) The skills involved in answering questions - it's not so much about the answer, but about the question
3) In detail, with regards to the question that was discussed in class, about the atmosphere and life

And that is about it... I hope :)

Blog rules

2009-01-19T20:13:00.000+08:00

1) Use Standard English

2) Your post must be in the form of a reflection and not a journal entry

GOOD LUCK :D

By the way, do take note that Audie will post a reflection for today's lesson and Register number 2 (Geraldine) will be posting a reflection for the next lesson which will be next Friday (30th January 2009)

Cheers,
Nurul

2009-01-17T14:34:00.000+08:00

Hey!! here it is, will try to find a nicer template if i have the time to.