IS2104

2009-05-29T06:43:00.000-07:00

Heyhey!
Sorry for the lag post and all :/
Anywayyy! Time to summarise the entire module! Basically, we covered 2 major spheres in this module: atmosphere &hydrosphere (:

For atmosphere:

Basically, we learnt about the composition of air -78% nitrogen, 21% oxygen and 1% other gases and learnt how oxygen is important to sustain life because it is reactive and forms compounds with various elements, allow humans to use it for respiration and life processes. Such a composition is ideal to sustain life.

Later, we learnt delved deeper into the presence of carbon dioxide in the atmosphere (0.03%) though the carbon cycle. Basically, we learnt that carbon dioxide is taken in by plants, then, as the plants & animals decompose, they give off carbon. Also, as they respire, carbon dioxide is given out. If dead plants & animals do not fully decompose they will form fossil fuels, storing carbon in the earth. Carbon dioxide is dissolved in the ocean as well, providing aquatic plants with energy. From this, we realize that plants & animals give off carbon when they respire and decompose, while plants take in carbon dioxide via photosynthesis and carbon dioxide is absorbed by the ocean as well to allow aquatic plants to respire.

We also learnt how man’s actions have interfered with the carbon cycle, thus, resulting in an increase in global warming as well. E.g. deforestation: results in less trees and thus, less carbon dioxide is removed from the atmosphere, increasing carbon dioxide levels and thus, increasing the amount of greenhouse gases, thus, resulting in global warming.

Then, we went on to learn about rain: frontal, relief and convectional rain. Essentially, frontal rain occurs when either warm air meets a cold front, or when cold air meets a warm front, resulting in the warm air rising and thus, adiabatic cooling occurs and it rains. Relief rain occurs when air is forced to rise when it meets a relief (e.g. mountain) causing adiabatic cooling, and rain to form on the windward side (facing sea) thus causing the leeward side (facing away from sea) to be dry. This may allow for the formation of deserts. Lastly, convectional rain is simply warm air rising and thus resulting in adiabatic cooling, and thus, rain. (:

Then, we learnt how to interpret climographs. Basically, its just describing how warm&wet a place is based on the data provided.

From the lesson on climographs, we realized that different countries have different climates, why is this the case? This is where the global air circulation model comes into play. Essentially, the global air circulation model looks like this!

which then results in the various different climates in the world, as well as the formation of deserts between the hadley cell and the ferrel cell. This is because air at the ferrel cell moves upwards while air at the hadley cell moves downwards, resulting in no adiabatic cooling occuring, and thus, no rain formation, making that area dry, and thus, forming a desert. * deserts are also formed due to relief rain (:

essentially, that concludes the atmosphere component!

:D:D:D

....now moving onto the HYDROSPHERE, which will be continued in the next post.

Waterfalls and Meanders

2009-05-03T06:10:00.000-07:00

Ok, right, time goes by and it was my second time to write the post.
In the 30 minutes lesson, we have learnt about the WATERFALL and MEANDER.
So let’s begin with the waterfall. The waterfall is a steep descent of water from a height. It usually found in the upper course of a river in the hills or mountains.
A WATERFALL=A STEEP DROP OF WATER
Formation of Waterfalls:
--It forms when a band of hard resistant rock lies over softer, less resistant rock.
--The softer rock is quickly eroded by hydraulic action and abrasion, causing the harder rock to be undercut.
--The hard rock overhangs until it can no longer carry its own weight.
--The overhang collapses and then breaks up in the water below.
--The great power of the water at the base of the waterfall causes a plunge pool to form.
--The bed of the river below the waterfall contains boulders eroded by splash back from behind the waterfall.

Some Facts of Waterfalls:
The tallest waterfall in the world is the Angel Falls. It is 979 metres high.
The highest waterfall in Africa is the Tugela Falls at 947 metres. It is found in South Africa.
Europe's highest waterfall, Utigard in Norway, is 800 metres high.
The Yosemite waterfall (739 metres) is the highest waterfall in the USA.

Secondly, we learnt meanders which are curves or bends along a river. It is usually found in the middle or lower course of a river.
MEANDER=A BEND IN A RIVER
Formation of Meanders:
A meander is formed when the moving water in a river erodes the outer banks and widens its valley. A stream of any volume may assume a meandering course, alternatively eroding sediments from the outside of a bend and depositing them on the inside. The result is a snaking pattern as the stream meanders back and forth across its down-valley axis.

Cause of Meanders:
Helicoidal Flow=Spiral Movement of Water
It will move eroded river load from the outer bank and then deposited much of it on the next inner bank of a river.
Top current: hits against the river bank and undercuts the eroded material.
Bottom current: carries the eroded material and deposits them in the next inner bank.

Yeah, I guess it’s all. Hope you can understand.
Enjoy the half day, heh heh.
Done by Violet

Joel's Post.

2009-04-27T07:39:00.000-07:00

Hello I'm being responsible and blogging today! (like right after today's lesson)
Haha hooray me, and for us! :D

So firstly, we learnt about THE RIVER PROCESSES today. :)
Basically, deposition-> transportation -> erosion.
Which means that, after deposition, if there is still excess energy, transportation will take place, and again, if there is still some more excess energy, erosion will take place.
Now, let me show you a graph, which would help to enhance your understanding! ;)

Critical erosion velocity (the Hjulstrom curve)

Okay, I hope that you've understand the first part of today's lesson.
Next, we went deeper into the transportation process!

Traction- Heaviest/Largest material is rolled along the river bed, and this requires the most energy out of all the subgroups.
Saltation- Sand-sized particles bounce along the riverbed in a "leap-frog" motion.
Suspension- Smaller particles (silt and clay-sized) are carried within the water by turbulent flow. Turbulent flow refers to water not flowing straight. :)
Solution- Some minerals will be dissolved in the water and will be carried in the solution, and this requires the least energy.

Now moving on, if there is still excess energy, erosion will take place.

There are 4 types of erosion:
1) Corrasion
2) Hydraulic Action
3) Solution
4) Attrition

Corrasion, or also known as Abrasion, targets the bedrock. The nature of corrasion is either called the 'drilling' or 'sand paper', which is the rubbing effect on sediments. The outcome of this process are potholes banks, which are wider and also smoother because of the 'sand paper effect'.

Hydraulic Action, or also known as Weathering, targets cracks. The nature of this process is air pressure. Air pressure increases when water seeps into the cracks, and air pressure decreases in the cracks when the water flows out. This will cause the cracks to expand, and it is an explosive process. The outcome of this process are collapsed banks.

Solution, targets the bedrock too. Bedrocks are rocks which have not been weathered yet. And the nature of this process is chemically driven.

Attrition, targets the sediment load. And this process takes place because of the impact of the sediment load constantly knocking against each other. The outcome of this process is the formation of smaller and rounder rocks.

Its the end! Haha yay aren't you glad, thats all! (for the erosion process) ;D

Now imagine a hill...
Okay nevermind, I shall attempt to draw it out for you on paint! :/

There you go! HAHA :)

Now to explain about the River Valley...

Upper Course takes the shape of a V-shaped valley due to mass movements, such as landslides and avalaunches. This is called vertical erosion, which deepens the bedrock channel, thus forming landforms like the Grand Canyon.

This beautiful picture shows the famous Grand Canyon of Yellowstone. The V-shaped valley is very obvious in here. :)

Middle Course takes the shape of a wider and flatter valley as a result of the sediments being already weathered, and broken down. This can also be named as alluvial. There is increased sinuosity, which means the distances widens and increases, which forms landforms like meanders and grasslands.

This picture shows a typical meander along the grassland. Notice that the grassland is much flatter and wider than the valley along the upper course. :)

Lower Course also takes the shape of a wider and flatter valley. The reason to this formation is exactly the same as how the middle course forms a wide and flat valley. At the lower course, floodplains and levees are the types of landforms formed.

The picture shows a floodplain, which is flat or nearly flat, and is adjacent to a stream or river. This position causes it to be flooded occasionally. :)

Hope you enjoyed reading this post!

Haha alright, see you people around.

By, Joel Tay (22)

2009-04-19T18:12:00.000-07:00

Sorry o3, totally forgot about this!

I'll be referring to the handout.

Page 230: Diagrams

If the shape of the drainage basin is as in the diagrams, then the gauging station is located at the bottom edge of the basin, in order to gauge the entire basin (if it was located at the middle, it would only gauge part of the drainage basin).

Hydrograph of Diagram 1:
-Short lag time
The highest discharge is at the bottom of the basin, due to the wider area and the large amount of tributaries.
Thus, the highest amount of discharge is within the "early" time zone (that is, it reaches the gauging station earlier), leading to an early peak.

Hydrograph of Diagram 2:
-Long lag time
The highest discharge is at the top of the basin, as there is a larger area at the top, so it collects more rainwater.
Thus, the highest amount of discharge is within the "late" time zone (that is, it reaches the gauguing station later), leading to a late peak.

Hydrograph of Diagram 3:
-Double lag time
There are two areas with the highest discharge, one at the top and one at the bottom of the basin, due to the wider areas here.
This leads to a double-peak as the two main discharges reach the gauging station at two different times.

Soil and water:
Base flow comes below the soil
Throughflow comes through the soil
Overflow comes above the soil

Ground water is below the soil and acts like a store of water (it is just above a rock layer), which is a long-term store (as opposed to surface water bodies) and can last for millennia. It is the source of water for wells. It is due to the fact that some rocks are quite porous and can "hold" water after it comes down through percolation, which comes after infiltration.

Throughflow is a less consistent store of water, as opposed to ground water, and it is faster than baseflow. It occurs through infiltration of water through the soil.

Baseflow is slower than throughflow, but it is more consistent than it, since it draws from ground water stores.

The drainage density of a basin is related to the efficiency of the flowing of water (or something like that). The higher the density, the more efficient the flow of water is, leading to a shorter lag time, and vice versa.

A bit on Pg 230, regarding the shape of the basin:
Long basin
-Consistent amount of water
-Early and late time zones both produce the same amount of water.
-Thus, there is an extended peak, as the water does not come all at once.

Round basin
-The discharge reaches the gauging station at around the same time.
-This leads to a short but sharp peak.

Calvin

Drainage basin and Hydrograph

2009-04-08T05:29:00.000-07:00

Firstly I would like the emphasize that in this post, I would not post pictures/excerpts from our geog textbook as I think it is redundant to do so since it isn't that hard to refer to your geog textbook.

To start things off:

Mr Faizal was once again explaining to us about the water balance because we were unsure about it. This time, he drew a diagram so I took it down...note that not all aspects of the water balance are illustrated here.

Storm Hydrograph:

(enlarge the photo to have a closer view)

This one caused quite abit of a stir...

Lag time: When a rain drop falls, the water level of a river does not shoot up immediately due to drainage. A rain drop still has to go through various processes occur before the water reaches the river. An example would be...imagine that you are a raindrop( so fun! ) and you precipitated down to earth. You land on the soil and infiltrate it. Thereafter, you would percolate and via throughflow, you reach the river. Hence, from this you can see, time was needed for the water to reach the river. This is lag time. Something to take note, a drainage basin with a steeper profile has less lag time and a drainage basin with a gentler profile has a longer lag time due to the speed at which the water reaches the river.
Rising Limb: After some time, water from the drainage basin would arrive at the river and it's water level thus rises.
Max. Capacity: When the river reaches it's maximum capacity and water is still flowing towards it, the river overflows its banks.
Recession Limb: When it stops raining(precipitating) some water within the drainage basin which hasn't reached the river continues its journey to the river. After which, the water level of the river slowly recedes and this is reason for the recession limb.
Rainfall Chart: The graph of the rainfall.

Yayy hope you understood it xD

Done by.. me. (:

Chunwai.

2009-03-31T07:58:00.000-07:00

hellow friends. mr heah was misfortuned to have been involved with an accident. it was shocking news for one and all. so, on behalf of the class, WE HOPE YOU GET WELL SOON and HAVE A SPEEDY RECOVERY mr raynard heah!!

carrying on, we had a relief teacher in place of mr heah, mr faizal. we were honoured to have a distinguished man on board njc's teaching staff. nice man he was, but unfortunately for him, he was not aware of which topic to start on and so went all the way back to the start. that was on adibetic cooling.

what i felt of the lesson was that it was a good revision for us (:

give me geography and i'll mug for it!!
thats my lifelong motto!

okay, guys. so i got a second chance at proving my worth in yet another blog post.
last lesson we covered the topic of water balance!

first of all. water balance is just another way of balancing things in life. dare i ask you to recall last term's MI topic of chinese medicine. one part to it was yin and yang. the concept behind water balance is the same.

it is an explanation of how water is never 'destroyed'. only 'transferred' elsewhere.

that is why P which is Precipitation/Rainfall will equal to all water 'transferred' through various processes.
those are, Q which is water flowing down above the ground (Runoff)
E which is Evapotranspiration, the water taken in by roots and transpired out back into the air

deltaS which is change in Storage of water in bedrocks or soil.

further details about deltaS, most importantly, you have to understand S is Storage of water in bedrock or soil. if the amount increases the next month, the change in Storage is positive.

and so, the equation of P = Q + E + deltaS is to explain where the water from precipitation goes. be it back into lakes through runnoff, and transpired back into the air by evapotranspiration, and stored in bedrocks or soil. the water in bedrocks, if increased means part of the precipitation is being stored there.

HENCE

this is to simplify all that i have mentioned in the post (:

2009-03-25T19:25:00.001-07:00

we went to the "hidden area" of nj today, near the container classrooms. and Mr Heah reminded us once again on how all systems are connected. the hydrosphere affects the atmosphere at some point, and vice versa. they are not in a vacuum, and neither can they be. if there was little or no rain, then soon plants will die, then the atmosphere will be affected due to the lack of plants, then the animals will die.. and the animals that prey on those herbivores die.. and so on. not to mention no rain means no cloud cover, and the temperature of the earth's surface will go up by alot.

we then went on to the lesson

we first explored the flow of water

lets imagine we are a raindrop. after finally falling, where will we go? assuming we fell over a forest, some of us may seep into the ground, some get intercepted by trees, some just hit the ground and flow off.

basically interception is just the tree, or grass, basically vegetation trapping the water, and preventing it from reaching the ground (though some will eventually)

but sometimes, when a raindrop hit s the leaf, it drips from one the the other! this is called throughfall. "through" the leaves, "falling" down.

if i flow down the stem/trunk then its called stemflow! flowing down the stem, essentially.

if i collect in depressions in the ground, as we see many times in urban areas, its called depression storage. if i evaporate/transpirate back, then its called evapotranspiration.

of course, i'll hit the ground also, and i'll seep into the soil! this is called infiltration. the ground though, also has an infiltration capacity, and infiltration rate. and sometimes if the ground doesn't soak me up fast enough,(too low infiltration rate) then some of me will flow off the surface. (which is also called overland flow. the term is self explanatory)

what is so amazing, is that concrete has a really really low infiltration rate/capacity, and it was really really dry (at the "hidden" area of nj), but at the grassy soil part, man it was wet! and life was teeming there. just shows how important water is to life. another example would be a desert, the ground is all sand, no soil, super little water, thats why there's little life!

sometimes when i (the raindrop) hit the ground, but its a hill/slope, then i'll move with gravity, downwards, but also along the "x" axis plane. this is described as throughflow.

then we went on to the drainage basin. the drainage basin is basically where the water is drained from, to a certain point. so as Mr Heah demonstrated, when we picked different points of a river, or in this case a drain, the drainage basin would be different. yup.

just a few thoughts. (not sure if all are right though)

why are drainage basins important? because if not for drains, we would experience floods! the water would just stay where it was, and we would have to manually transport every drop away. good thing that things were made in such a way that naturally, somehow, the drainage basins work, and we not get a flood every time it rains. of course urbanization has changed alot of things, (lots of concrete around..) and we now need lots of manmade drains, to prevent flooding.

allow me to talk a little about the little excursion we had with Mr Heah after the lesson, where he took us to places to find plants through the concrete ground. somehow, as long as there's a little bit of water, life has an opportunity to grow, and when the little hardy plants die, there is a some organic material there, for other plants to grow, and soon, (forgot what the term was) more and more life can be found! if you go to the level where our class is, coming up by the staircase near the bookshop, and turn left, look around, you will find a pretty plant, with stem and all. amazing.

jonathan

Gan Hao Qing JH403 16 Important of Water for Life

2009-03-24T02:48:00.000-07:00

Yesterday was the beginning of a very EXCITING term 2! During Mr Heah’s lesson, everyone was very lethargic, as it was the first day, obviously. Plus the fact that we came in late, we probably had only 10 minutes of lesson time.

We shouldn’t just memorise facts, as Mr Heah always says, it makes him want to ‘vomit blood’. Don’t just read through the textbook and remember everything. The most efficient method is to GET THE IDEA! Get the main idea of the whole concept. To do this, you may want to draw a mind map or do simple things such as highlighting notes when reading and writing them down again on another piece of paper and rephrasing it till you’re comfortable with it.

This is roughly how it goes
1) Get the primary ideas, which are the broader terms.
2) From these primary ideas, break them down to secondary ideas
3) Lastly, break them further into tertiary ideas.

OKAY! Our 10 minute lesson was on the Importance of Water for Life

If we were asked why water is important to life, most of us would probably say that without water there is no life, and maybe a little more. But we learnt much more today!

For example, scientists search Mars for signs of water to see if there is/was life. They think that there are signs of water in Mars as water shapes the surface, and they found signs of it.

There is more life existing on the equator because tropical rainforests are there which are warm and wet. Water is LIFE! Almost.

I guess I never really appreciated water for its importance. I just took for granted that I needed to drink water because I felt thirsty, that we needed to shower with water because it would cleanse us. But water actually does much more than that, it has a large temperature range so that cells in our body do not explode or become all shriveled up. It allows marine life to exist as during winter only the top of the surface of seas or lakes freeze. Water has many amazing qualities that other liquids cannot replace.

Importance of Water for Life? Very Very Very Very important. That is why we should save us much water as we can! Conserve :D

HOMEWORK!
Search Two primary ideas from “Importance of Water for Life” worksheet
Then branch them out into secondary ideas
Lastly, the tertiary ideas!

Gan Hao Qing JH403 16

friday, march 6, 2009

2009-03-09T01:21:00.000-07:00

I deeply apologise for this post being so late. anyway, what mr heah taught on friday was the 'fusion' of everything he taught for quite some time. it combines the knowledge the tilt of the earth at 23.5 degrees. as geographers studying physical geography, we want to explain why deserts are found at the tropics, and not the equator. logically if the earth was not tilted and there were no land masses and the earth did not turn, the people living around the equator (us) would be hot =D But, why are deserts found at the tropics and not at the equator where most sunlight is 'supposed' to strike the earth with the least surface area and the highest intensity. however, this is the real world we are living in, not some lala land where everything is at its ideal state. however, due to the fact that this is only secondary school level, we did not study the impact that land masses have on the climate and winds.
However, we studied the effect of the tilt of the earth had on the location of deserts. the tilt of the earth causes the areas near the north and south poles to experience 24 hours of night and day one day a year. we looked at the koppen-geiger map and realised that the location of deserts are at the places where the sun shines with the smallest surface area. also, we learnt about the definition of a desert, which is a dry land mass. we learnt about the three cell diagram, which is simply how air raises from the equator due to its heat, moves northwards, cools, and moves down. as air moves up, adiabatic cooling is allowed and hence causes rain. in the equator, it is wet due to the hadley cell pushing the air up and the presence of adiabatic cooling, which causes rain. however, at the tropics, the induced cell, also known as the ferrell cell, makes air move downwards instead of upwards. therefore, no adiabatic cooling occurs and therefore there is very little precipitation. this is the main explanation for the presence and location of deserts. there is also the polar cell, which is formed due to the absence of heat at the poles, which makes air sink and move to somewhere near the circles where they get warmed up slightly and rise again. the induced cell, as mentioned by him, is special because it is not formed by the heat, but by the movement of the air. the movement of the hadley cell and the polar cell causes the air at the tropics to move in a certain direction, therefore the use of the term 'induced' cell.
after that, mr heah took out a globe and taught us about the various kinds of data a globe could provide a reader with: the economic data, the population, the presence of land masses and many more. he also used the two bright suns to show what happens to the north and south pole during one day of the year, which i think is 21 of january and 21 of december. he used the globe to show us the essential points of what he taught throughout the whole term in diagram form. he also mentioned that at the equinoxes, there will be 12 hours of day and night ( spread out evenly)
lastly, before he left, he provided us with some information for the upcoming assessment week (heehee), telling us that we should know about the various housing estates in singapore as this is human geograhy that we are being tested on. he also recommended playing the 'geo challenge' game on facebook. the game has four parts. the first part requires you to match a country's flag to it. the second part requires the player to identify the countries from the shape of the country's land. in the third part, we are given the world map which from it, we have to identify different countries and parts of the coutries by clicking its location on the map itself. in the last part, we have to identify the countries from which different landmarks are at. it is a very interesting game and improved my geography too =D

global air circulation----by CHEN PENG

2009-03-04T17:00:00.000-08:00

Today we learned the model of global air circulation. Mr heah started the lesson with two questions: Where can deserts be found in the world and why are they there. As we know, the hottest zone in the world is the equatorial part, but the desert cannot be found in the equator and a kind of desert known as cold desert also exists. Therefore, the desert doesn’t depend on the temperature very much. The deserts are form mainly because of the dry climate.
As we can see in the world map of Koppen-Geiger climate classification, the deserts can always be found in the subtropical zone. This is because this zone is the driest in the world due to the global air circulation.
We want to find the general rule of the air circulation, so that we have to control some factor. We assume that the earth is complete uniform and the global reception and loss of energy can cause the temperature gradient of air in equator and poles. If we also ignore the rotation of the earth, we can get the single cell model (shown in figure 1p-1). Since the temperature of the air in the equator is higher than that in the poles, the pressure of the air in the equator is lower than that in the poles. So the air in the equator will flow vertically to the upper level of atmosphere and flow towards the poles. When the air reaches the poles, it will sink and flow back to the equator again.

However, the single cell is too simple to describe the air circulation. Now we can think about the factor of rotation of the earth, and we can get the three cell model. (Shown in 7p-2) Since the Coriolis force affects the direction of the air flowing, the air will be deflected no matter in the bottom or upper level of the atmosphere. By about latitude of 30°, the direction of air flow is nearly parallel to the latitude. This will cause the accumulation of air, so that some air is compelled to sink and move to different directions so that some air can flow back to equator to complete the Hadley cell. The polar cell is similar to the Hadley cell but the air in the pole sink to the bottom to start the circulation. However, the Ferrel cell which Mr heah taught us is a bit different from the one described in the online readings. The online readings say in latitude of 30°, the air in both of the upper and bottom of atmosphere flows towards the poles and the air in the bottom will rise in around 60°of latitude. However, Mr heah taught us the upper air in the Ferrel cell will flow towards latitude of 30°. I think the online readings are correct, since if the upper air in the Ferrel cell flow back to latitude of 30°, the polar jet stream cannot be formed.

These are the main things we learned today. At the end of lesson, Mr heah ask as to think why the deserts can be found in the subtropics. I think it is because the zone is in the subtropical high pressure zone which is created by the upper air sinking by around latitude of 30°. It is also in the trade-wind zone. So the air sinks to cause the high pressure and temperature and the relative humidity decreases so that the cloud and rain cannot form easily. That is why there are so many deserts.

(Source of pictures: PhysicalGeography.net)

Geo Lesson Reflection By Zili

2009-02-25T05:02:00.000-08:00

Mr Heah didnt come, once again.

A pretty female teacher came (sorry i forgot her name) and planned to show us a DVD. However, since our projector sucks, she could just do revision with us first. We recapitulated what we have discussed last lesson, the two questions which Xinyi has already pointed out in her post. I really think the teacher is very good. She made me much clearer about what we have learnt through explaining it as a system. For example, the exist of seasons is not because the difference in distance between Earth and Sun, but the intensity of sunlight. The tilted axid of Earth causes one place to experience different sunlight intensity during different time within a year. That is quite fun!(:

She answered some other questions we asked and finish the revision. Then she decided to let us watch the show directly through her computer screen. We squeezed together and watch although not everybody could see clearly. The position I chose is just ok, so lucky I got things to write now!(: The video we watched is called The Private Live of Plants. It showed us many beautiful scenes of plants and it was that enjoyable.

The explorer brought us to a mountain, at where he found some interesting plants growing in the rocks. It a kind of algae plant which develops slowly in the rocks and then makes them look fantastic. He also found some tiny flowers struggling in between the rocks. Oh man, plants are so strong! They can even survive within such a harsh environment. Plants can adopt their growing condition no matter it is cold or hot, wet or dry. The explorer then shifted to another mountain all covered with snow. We saw some trace of plants but it seemed they have already died under the snow. However, the video used fast-foward effect and made the time fly. The snow gradually melted and we saw the leaves and stems of the plants. They turned back to live! And then sunshine came out, the plants growed further and even started to bloom. The flowers were that cute! They always faced the sun and followed its movement. And at night, they folded their petal. Then we travelled to a extremely hot and dry desert. The plants there all got their own way to deal with the weather. For example, the cactus got needle-shaped leaved to prevent excess loss of water and they got peat-trunk to store water. Another dont-know-what-it-is-called plant buried its main body deeply in the ground and just sent its transparent "window"to the surface of ground to absorb the sunlight for its photosynthesis. Sometimes, it does rain for even 20 years, but the plants could even survive and grow super fast when precipitation comes. The explorer poured a cup of water to a plant which seems have been thirsty for quite a long time. It immediately extend its leaves and stand up. Before long, we saw the flowers just came out. Since in desert, there is not much food provided for plants. Some of them learnt how to capture insects and get nutrients from them. This types of plants are normally quite beautiful and fragrant so that they can attract their preys. The last place the explorer brought us to is the hot rain forest in Mountain Roramia. We saw the mangroves growing in the water. Sometimes the tide might submerge the mangroves and them need to hold their breath until coming out of the water. It is so cool! And also, they can drop their seeds directly into the water, some of the seeds just get into the mud and grow while others are brought away by the waves and develops their generation away from their parents.

Around our Earth, climates are different according to the location. Plants in different place respond to the climate and form their specilized features. Our nature is a system and all parts of it are affecting each other.

XinYi's blogpost

2009-02-23T06:50:00.000-08:00

Mr heah didnt come today!

today we had to answer 2 questions.
1) Explain the distribution of Earth's Climate.
2) Why are there seasons?

We have learnt in previous lessons that is it crucial to break down the question that we are going to answer in parts. By doing so, we will be questioning the question. A recap of what we did in class for question 1: what is distribution and what is climate? You should know the answers already, since we went through them in class.

Then, we were split up into groups to answer either one of the question and my group had to answer question 2. For the Q2, you may ask what are seasons? I believe that most of you know what seasons are so i don't think i need to explain. (FYI, this is what i got from wiki "A season is one of the major divisions of the year, generally based on yearly periodic changes in weather")

Reading the notes provide us with sufficient information to answer the question. But if we have to explain our answers to our classmates, we can't possibly read out the entire stack of notes to them. So when we are asked to answer a question using the information given, we have to sift out the important points in the notes tso as to answer the question.

Today, when we were asked to explain to the other half of the class why there are seasons, one of the groups simply used one sentence from the notes to answer the question. (The sentence is "The changing orientation of the hemispheres with regard to the sun is the true cause of the seasons".) At first, i thought this was an excellent answer, but when i tried to use this sentence to explain to another group, i realise that is it not so easy to understand that sentence! some people would just go like "huh?" when they read it. (which they did. heh.) There is more than just answering the question, we have to understand the process which takes place as well. The sentence above does not explain how the changing orientation of the hemispheres with regard to the sun causes the different seasons. I believe that using one of the diagrams in the notes (figure 2-11) to explain why there are season is will be much more effective, allowing for the group to better understand the concept and to answer the question as well.

All in all, when we are answering a question, we can't simply copy and paste from the notes. We should understand the infomation on the notes and answer the question based on our understanding, possibly even rephrasing it in a suitable manner. Afterall, what mr heah have been emphasizing that we should understand these concepts so that we don't end up mugging and memorising like mad before the exam! :D

GEOG REFLECTION BY TABITHA! :P

2009-02-19T06:47:00.000-08:00

Yay! My turn to post! Heehee!

SO! Today we learnt how to answer questions about climographs! Before today's lesson, I looked at the example for Singapore's climograph and thought,"Oh no! It is impossible to memorise such a long paragraph full of information on that climograph!" Fret not! Because after the lesson, I've learnt that with a little bit of common sense and understanding, climograph questions are not all that scary!

Firstly, we have learnt that climate is all about how wet and warm the place is. Therefore, a climograph will show how wet and warm a particular place is!
These are some things to take note of when answering climograph questions:
1. Think of wet and warm. Be concise in what you want to say, do not write long sentences which would complicate the simple meaning you are trying to bring across.
2. Notice the shape of the graph of the temperature, those in the northern hemisphere would have a different shape of those in the southern hemisphere.
3. Check for any abnormalies! For example if the shape of the temperature graph does not fit or correspond to those of its seasons.
4. Don't just use wet, dry, warm and cold. Add adjectives to show how wet or dry like MILDLY wet or VERY dry or INTENSE precipitation.
With these points to take note of when writing, your answer will be more precise and have less mistakes!
That's all for the points!

Today, we have also learnt that the shapes of the temperature graph is affected by which hemisphere it is in and the season too. The climographs of countries in the northern hemisphere have a "n" shape while those in the southern hemisphere has a "u" shape. Also, the amount of precipitation affects the temperature. With little precipitation, the temperature would be high. What I've found interesting is the part on Mcmurdo station. It seems that its temperature graph is flatter when it is between April to September. This is because it is positioned such that when the earth rotates on its axis, it will not recieve any sunlight at all thus the temperature remains almost the same because it has no season as it is not recieving any sunlight.

I have certainly been enlightened today because the climograph question originally got me worried since there was so much information needed in that short paragraph. I was worried if I would be able to remember what kind of information to include inside or whether there was anything extra that I was writing into the answer. However, after the lesson, I got a better understanding of how to answer the question and why I must include this answer. Now it seems a lot easier because after writing something, I can easily link it to another piece of information on the climograph and include it in and so on. :D

Haha! Now everyone! Comment on this blog entry the climograph description for the different countries! Yay!

blog post by Li Qin

2009-02-16T06:03:00.000-08:00

Do u fully understand climate change? How has the climate been changing so far? In order to answer these questions, it is important to know about the types of climate and their distribution throughout the world.

Firstly, we have to understand the difference between climate and weather. Both refers to the atmospheric conditions of a specific location with the only difference whereby climate describes the condions that occurs over a long period of time while weather decribes that of a short term of time. The atmospheric condtions generally refer to how warm and wet the place is.
In order to know about the climate condtions of a country, the easiest way is by referring to climographs. So what is a climograph? It is a representation of the climitic conditions in that particular country. It contains the values of the monthly average temperature and the monthly average rainfall of that country.

Below shows how you can read a climograph:

In order to describe this climograph in details, below is the format that you can follow
*refer to the above mindmap on atmospheric condtions for describing climograph

-the general temperature pattern (constant or not?)

-the range of the temperature

-the general pattern of the precipitation(even? high?)

-indicate the dry season (months with lesser rainfall as compared to other months) with the approximate range

-indicate the wet season (months with more rainfall as comapred to other months) with the appoximate range

-finally, the climate type of the country (temperate or tropical etc) Above shows the general division of the climate types at different parts of the world. (Remember what's the other term to describe the tropics? (ans: torrid) and polar regions?(ans: frigid==> with courtesy to mr.heah's explanation =D. If it is easier to remember the climatic conditions of each climate type with this interesting explanation!)

I feel that it is very important to know the climatic conditions of the different countries for very basic reasons such as traveling, migration etc. By knowing the climatic condtions, we can also infer about the economic activities such as the types of agriculture cultivation. Remembering how space shapes people, we will able to know about the living lifestyles and the cultures of other places too. Just by knowing the climatic condtions, we can get to know so much more about other places. Isn't it amazing?

Extra:

When you hear a thunder roaring, tell your surrounding people that the process is called nitrogen fixation! *with courtesy to mr.heah's explanation

(lightning is 5 times hotter than sun surface-->heats up air-->burns nitrogen-->expansion-->loud explosion (thunder)-->nitrogen dioxide-->dissolves in water-->nitric acid-->fall as rain-->seeps into soil-->bacteria converts nitric acid to nitrates-->absorbed by plants as nutrients-->taken in by humans)

Friday, February 13,2009

2009-02-14T19:26:00.000-08:00

Today, we learn about 3 types of rain: convectioned rain, frontal rain and relief/orographic rain.

Frontal rain:

∗ Warm air meets cold air.
Cold air meets/collides/move into warm air.
∗ Warm air is force to rise.
∗ Adiabatic cooling

∗ Rain
∗Located at temperate regions.

Relief/ orographic rain:

∗ Moisture – laden air from the sea.
∗ Relief of the land/mountain forces air to rise.
∗ Adiabatic cooling
∗ Water vapour condenses.
∗ Rain leeward side.
∗ Rain shadow – dry ( ↓ moisture, air sink )

Convectioned rain:
∗ Heat from sun to ground.
∗ Heat from the ground heats the air above.
∗ Evaporation from the sea.
∗ Warm air rises.
∗ Adiabatic cooling.
∗ Rain.
∗ Located at tropical region.
∗ Only occur in the afternoon and evening.

Above are the summary and diagrams of the 3 types of rain. In today lesson, Mr.Heah let us discuss first, gave us some clues, and then we had to come out with the answer based on our own knowledge. At first, everybody said they were not sure of their answers or it would probably be wrong. However, all groups got it right in the end. Mr.Heah proved his point here ☺, which is, “In fact, we know everything in geography, it is only that we haven’t organized our knowledge” ☺

geog post by qizhen(:

2009-02-09T03:49:00.000-08:00

okay, today we watched a video, "The inconvenient truth" and the blog post will answer the question "To what extent should we be concerned about carbon dioxide emissions?" based on it. Basically, our Earth is livable due to the presence of the atmosphere. However, it is very thin, and vulnerable such that we can change its composition. Although one may arue that the atmosphere is really huge, it is actually only as thick as a coat of varnish on a ball, imagining that the ball is of the sanme size as the Earth, so ya, our atmosphere is really thin. Apparently, our atmosphere keeps our Earth warm by retaining some of the sun's radiation, however, it is thickening as increasing carbon dioxide is being emitted. This thickening of the atmosphere is resulting in more outgoing infrared radiation to get trapped and thus leading to global warming.

The concentration of carbon dioxide is also directly proportional to the temperature. In 650, 000 years in the past, the carbon dioxide level never exceeded 300 million parts per million, now however, it far exceeds 300 million parts and this level is predicted to go up for the next 50 years or more. More carbon dioxide in the air will also just mean a higher tenperature of the Earth as more heat is trapped from the Sun. Global warming thus occurs.

Global warming is having negative effects world widely. One example is the rise in temperature leading to the melting of glaciers world-wide and the Himalayas. However, the spring water from the Himalayas is providing 40% of the earth's population with water supply, and the melting of the whole Himalayas will just result in this 40% without water.

One of the effect of global warming that is often unnoticed is the increase in precipitation worldwide. When there are storm conditions, all these precipitate will just come down together. One example is the rain in India when there was 37 inches of rain within 24 hours, resulting in the biggest downpour ever in India. However, the precipitate is often relocated due to global warming, causing floods and droughts to occur simultaneously in neighbouring provinces. lakes are also dried up and water is evaporated from oceans and even soil. People then have to be relocated as where they live are often determined by climate patterns and global wamring is changing these patterns.

The Arctic is one of the places which is receiving the fastest impact of global wamring. Permafrost is thawing, resulting in the collapsing of buildings and trees not standing straight. Moreover, in 1970, there was a decrease in the amount, extent and thickness of th Arctic ice cap by about 40%. By an approximate 40 to 50 years time, it is guessed that the ice cap would have be completely gone.

With global warming, polar bears are also for the first times, reported to drown. This is due to the decrease in ice in the oceans. When the sun shnes, the ice reflects back the heat while the open ocean absorbs the sun energy. Withthe rising temperature, the water absorbs more heat energy and warms up, thus melting the ice into open waters. As a result, there is no more ice to reflect the sun's energy but all has melted to become water, absorbing the heat energy. This causes polar bears to swim for miles looking for ice, yet being unable to find one and drowning.

There are also planetary effects which will be affected. Heat is regulated by wind and ocean currents. These currents are formed when water sinks due to higher density from the salt content and becomes cold water. The cold water sinks at 5 billion gallons per second which results in the direction of the currents to go South resulting in the currents. With this, an ncrease of 5 degrees of the Earth, the equator increases by 1 degree while the poles increase by 12 degrees and the Earth's average temperature is 55.8 degree farenheight. However, these currents can be disrupted. For example, when the dam at the Great Lakes(melted water) broke, water gushed out and reduced the concentration of salt content in the water, causing the currents to jam.

Glabal warming can also result in a change in seasons, like for the hatching seasons of animals. In the past, the peak of hatching seasons for the birds and worms are the same, thus the birds will always have enough food to eat. However, recently, the peak of the hatching season for the worms are earlier and the hatching season for the birds is unable to catch up with it, thus leading to hunger of the birds.

Number of days with frost are also decreasing with the years. Pine beetles which are often killed by the frost can now survive more due to the days of frost decreasing. This will then lead to the destruction and devastation of the pine trees): Furthermore, due to higher temperatures, mosquitoes can climb to higher altitudes and new diseases such as SARS are emerging. Diseases such as Avian flu and West Nile, which were under control for a very long time, have also re emerged. Coral reefs have been bleached and organisms dependent on it are also affected.

Someone also mentioned that ice shelves in Antartica breaking is a great alarm bell for glabal warming. That is exaclty what is happening, one example is Larsen B. With this breaking ice shelves(floating ice), pools of water used to find the problem are increasing. Land based ce supported by the floating ice also falls into the ocean, increasing the sea level. One analogy provided was the one of ice cubes in a cup. When the ice cube is already in the liquid, melting of it will not raise the water level. However, when the ice cube is resting on the top of other ice cubes, melting of the paricular ice cube which is not in contact with the liquid, the water level will rise and lead to over flowing. This is what is happening in the oceans))): Also, lakes which were expected to refreeze form moulins instead..

Another effect of global warming is the melting of greenland reulting in the map having to be redrawn. This is because of the melting of Greenland keeps occuring, other places such as San Francisco, Netherlands, Beijng, Shanghai, Florida,Calcutta and east Bangladesh will be underwater. these places which have approximately 100 million people will then have to relocate the people.

Outside the video!!
right, Mr Heah said that the tipping point is the point when positive or negative feedback has no more power. For example, when a body is super super super cold, it can only shiver this much and will thus eventually die. yeps, of vice versa when the body is super super super hot, it can also only perspire this much before it finally dies):

okay, so yea, tt's bout it, except that in a essay, we must not just keep wondering "WHAT points" to write but "WHAT TYPE of points" to write so that we won't keep writing and writing thinking that we have a lot of points only to realise later that all the points are just different examples of A SINGLE point(:

Geog Post By Huiqi

2009-02-05T06:44:00.000-08:00

Geog lesson reflection -by Amanda

2009-02-03T09:00:00.000-08:00

Yesterday's (monday 02/02/09) lesson was mainly about the question we were given: How severe is the impact of man on the carbon cycle?

We learnt during the lesson that the carbon cycle is like a system, and with systems, balance/equlibrium is tried to be achieved. Mr Heah gave an example of the human body whereas when it is cold, our body would shiver to gain heat. And when it is hot, our body would perspire to lose heat. Either negative or positive feedback occurs when the system is not in an equilibrium and the system would try to discourage change during negative feedback, and would encourage change during positive feedback. An example Mr Heah gave for positive feedback is labour contractions. When the womb (is it the womb? Oops not sure!) muscles contract, postive feedback is sent to the muscles, producing a substance. The substance causes the muscles to contract even more, causing more pain.

After Mr Heah talked about the systems, he talked about the question in our assignment paper. How severe is the impact of man on the carbon cycle? He mentioned that most people would just Google/Wiki the term carbon cycle, and talk about it in the essay. But in the end, they'd get a B grade. Instead, what we should do is to break down the question and question the terms in it (for an A grade essay!).

The carbon cycle is actually a balanced system, but with the inteference of man, the amount of carbon increased greatly. Instead of solving the problems, man is making it worse. Within the cycle, man are adding on to the amount of carbon by burning up fossil fuels, as well as producers. Plants, the only producers, are being burned down to make more space for man, and this is causing deforestation. Not only that, plants actually remove CO2, but without them, not only would CO2 be unable to be removed, it is added on. All this extra carbon dioxide is being added on to the atmostphere, causing many implications, like on the weather. Now the main thing is to solve this problem and stop adding on carbon dioxide to the atmostphere. Solutions should not be making things worse and should be effective. So what should they be? We'd have to think about it.

Overall I think yesterday's lesson was very enriching because what was taught to us would aid us a lot in our assignment. From how systems work, to how we should break down the question to answer them part by part. These pointers would help us analyze the assignment better and guide us along better as well.

Geo lesson reflection --by Zheyuan

2009-01-28T04:10:00.000-08:00

Basically, we did the mindmap in groups and talked about carbon cycle today.

At first, we discussed and reorganised our mindmaps in groups. Forturnately, my group was chosen to present our mindmap to the class.Based on our own mindmaps, we have come up with a mindmap that combine the important points in our mindmaps, clearly presented by Alissa, evaluated by Li Qin, and was givin a quite high score.

Back to the topic, the question here is : How is atmosphere essential for life?

At first, when i do my mindmap, I just read through the notes given and copy all the useful points on a piece of full scap. But it looks like an essay, rather than a mindmap. However, after today's lesson, I realized that knowing the facts does not really answer and explain the question. What I should do is to think before I draw a mindmap. What do I know about the topic? Is it important enough to be in the mindmap? and so on and so forth.

Questions like this could help me organise ideas and give a clearer way of seeing the whole big picture.

Since, everyone must have known the concept and the mindmap very well, I would not go into that part further.

Something that is quite new to me is the carbon cycle part.So I'll try to describe it in my own words, hopefully, everyone could correct me if anything is wrong.

In the atmosphere, there is 0.03% of carbon dioxide, which is very little, comparing to other gases like nitrogen and oxgen. However, it is important since it's the basic material for plants to photosynthesize. Carbon dioxide is turned into sugar, mainly glucose and starch through the process of photosynthesis and stored in the plant. Animals will consume plant, use the sugar to provide energy to their body. After decomposition of animals' dead body, carbon will return to atmosphere. Besides, carbon also returns to atmosphere in the form of carbon dioixde as a product of animals' and plants' respiration.

If the dead plant or animal is not completely decomposed, they will turn into fossil fuels. In this way, carbon will be stored in the earth for quite a long time.

Carbon dioxide in the atmosphere also dissolves into the ocean, providing aquatic plants energy, and starts the carbon cycle in the ocean. A different way of carbon being stored in the ocean is that carbon is taken by oyster, forming the seashell. After the oyster died, the seashell will not decompose, in stead, it will become sediments and finally form the limestone--a kind of sedimentary rock.

It seems very easy to understand the carbon cycle with reference to the mindmap.And to understand everything in a system is easier than memorizing the facts.

Despite all of this, Mr Heah mentioned the regulatory force in the nature that keeps the carbon cycle balanced. Well, I have not figure out that yet. And still, I wonder if the earth was formed with the specific percentage （0.03%） of carbon dioxide in the atmosphere. If it's not, was there a regulatory force? And what's the use of regulatory force if there's no consumption of carbon ( when there's no animals, or plants)？

Hope my question is answered soon.

Geo Lesson Reflection -- by Viona

2009-01-21T02:10:00.000-08:00

Today Mr Heah didn't come to class. So we watched a video about the Earth's Atmosphere. It was pretty interesting. It was about this traveller who went around the world.

Let's clear this up. I will refer to this traveller/host of the show as he throughout this post. Not in any order, I will try and describe the entire show to everyone.

He travelled to Siberia where he found trapped methane underneath the ice. He and another lady dug through the snow to the ice surface of a lake I think, and they found many air bubbles trapped in the ice. To test whether the gas in the bubbles were methane, they set fire and see if it would burn. It was quite a sight. Fire on ice. Methane is more potent than Carbon Dioxide. If the ice melts in Siberia and these large amounts of methane in the permafrost gets released into the atmosphere, it would be a disaster.

He also took a fighter jet and flew into the atmosphere. When we see shooting stars, it is actually a meteors burning up in the mesosphere. The mesosphere protects us from all meteors that comes crashing into Earth. The stratosphere is the layer where it absorbs most harmful rays from the sun protecting us. And there was this guy who took an air balloon up into the sky and went even higher than he did. And when that air balloon guy reached a certain level, he jumped out and experienced free fall for a few seconds.

Next there we saw this huge cloud and there was this man who sky dived during free falling. Pretty interesting. Shows us that we can "surf" in the sky as he called it. Instead of falling straight to the ground, he can maneuver the board that was attached to his feet to move horizontally.

Then there was a theory about how the earth atmosphere was formed. It started of with countless of eruptions from volcanoes spewing out carbon dioxide and methane. Then came an organism that started to photosynthesis giving our atmosphere oxygen. As the amount of oxygen increased, the more and more organisms come alive.

There were also many others about the sahara desert blowing sand which contains many minerals to the Amazon rainforest (I think). And there was a one on the lightning at a high mountain range, Andes. It was showing how lightning looks like at different layers of the atmosphere. There was another about the rust forming under the ocean as oxygen got produced and reacted with the iron under water. After many years, the ocean dried up and left behind rocks with bending where we can see the different layers. We also saw how our atmosphere got shaped over time by the wind and sand providing amazing natural landscapes (Arizona).

All in all, today's lesson was fun and enriching. The video was informative and showed us a lot of the world and the earth's atmosphere that we don't know.

A reminder to the class: Do up your mindmap before the next lesson because Mr. Heah will go through it then :)

Geo Lesson Reflection--by Deng Xuan

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

Today Mr. Heah taught us the basic knowledge about the composition and structure of the atmosphere. At first, I wondered why we should learn such a common knowledge that everyone knows it in primary school. But later I noticed that it is not as simple as I think.

It is definitely true to say that the atmosphere is essential for life, but why it is? You may say that because it has oxygen and people need oxygen to stay alive, but why oxygen is, why could not be nitrogen since it constitutes 78 percent of the atmosphere? All of these I have never questioned myself before. That’s why when I started thinking them I found that Geography is more than memorizing. It can be linked to other scientific subjects and remembered by thinking logically.

The composition of air basically includes three parts: 78% of Nitrogen, 21% of Oxygen and 1% of other gases. The oxygen plays an important role to sustain our life because of its reactive property. It can form compounds with lots of elements and moderately soluble in water so that we can easily use it as respiration and other necessary biological activities. Other gases like nitrogen and helium, is either too stable or too reactive.

However, there is another gas in atmosphere that only constitutes 0.036%. It is carbon dioxide, the so-called waste product of all living creatures. Mr. Heah asked us what if there is less carbon dioxide in the air. As my opinion, I do not think it is good for us although it may help solve global warming or whatever. Carbon dioxide is as important as oxygen in the world. It is the key of the carbon cycle which helps balance the spheres and interacts properly between the layers. If there is less carbon dioxide in atmosphere, it will also be less carbon dioxide dissolves in the waters of the hydrosphere. Thus, the land plants and aquatic plants can hardly survive without enough carbon dioxide to photosynthesis and make food.

Otherwise, we also learnt the structure of the atmosphere. It has five spheres: troposphere, stratosphere, mesosphere, thermosphere and exosphere. There was one question that puzzled me a lot and I hope someone can provide an answer. Actually Mr. Heah mentioned that it is something about the difference between temperature and heat.

The question is “why the temperature at the thermosphere is higher than 1200 degrees Celsius, yet you would freeze to death up there?”