Vegetation

When i first hear the words , "natural vegetation", i was thinking, "hmmmm. it  must be some boring chapter about bushes and trees growing naturally " But, oh well, looks like theres more to that in natural vegetation!

NV-vegetation that has grown natually and not man-made.
Why is NV important to us?
- provides oxygen
-home to some animals
-medicinal properties of some trees
-makes Earth looks pretty ( thats what i think, but yeah :D )

in total, there are 7 types of NV.
1. tropical rainforest
2. temperate deciduous forests
3. temperate coniferous forets
4.tropical savannahs
5. temperate grasslands
6. hot deserts
7. cold tundras



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Effect of W&C on NV
-temp: affects rate of vital processess ion plants
-rainfall: for survival/photosynthesis

* The NV will adapt to the climate by having necesary and different characteristics.

for example:
the NV in the tropical rainforest will have characteristics like:
-having waxy,drip-tip leaves
-braod surface
-hairy surface
-high density and biodiversity
-sparse undergrowth

whereas, the NV in a TDF:
-thin,delicate leaves
-broad leaves
-thicker and fuller canopy crowns during summer
-thick,rough barks
-shed leaves during autumn

the NV in TCF:
-cone-shaped crowns
-supple/flexible branches
-small,needle-like leaves
-evergreen
-thick barks
-shallow root systems
- hard leathery fruits

* adaptations are related to surviving
* adaptations are related to the changes in climate

Climate.... how much do you know about them~

Climate, is about a long-term trend of the weather over a long period of time. The elements of weather plays an important role of how the world's climates are classified into. there are 3 types of climates:
1. tropical
2.temperate
3. polar
  these three climates are distributed differently on the map.
For the tropical climate:
latitude- near the equator, between tropic of cancer (23.5degrees N), tropic of caricorn (23.5 deg S).
characteristics-temp:20-30 degC throughout, high rainfall, 1000-2000mm annual rainfall.
the reason why the its hotter in a tropical climate, is because, the countries are at the equator, so when the sun rays strike the earth's surface, sun rays are concentrated over a small area, thus heat is more intense.

temperate climate:
latitude- betwwen tropic of cancer and arctic circle, between tropic of capricorn and antarctic circle.
characteristics- 4 seasons in 1 year, temp: 34degC, winter, below 0degC ( not constant ), moderate rainfall, 300-1000mm annually.
 in a temperate climate, precipitation and temp fluctuate a lot, unlike the tropical climate.

polar climate:
latitude-between arctic circle and north pole, between antarctic circle and south pole.
characteristics- 4seasons in a year, temp: summer ( below 0degC), winter:( lowest of -89.2degC) , low rainfall of 110 mm annually, when N.hemisphere tilts towards the sun, 24 hours of sunlight at N.pole while the S.pole is in total darkness!


The question Ms J asked was can climate changes fluctuate in the same way weather conditions vary daily?
Now, heres my answer :
  Well, weather changes on a daily basis/hourly basis, but climate is the weather trends over a long period of time. thus, climate changes cannot fluctuate in the same way because it remains consistent for decades maybe even centuries. So, nope, it cant. climate changes cant change and vary like the weather conditions.

Weather

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What is weather?

. Weather is the state of the atmosphere, to the degree that it is hot or cold, wet or dry, calm or stormy, clear or cloudy.Weather is the change of temperature over a short period of time(daily). Weather is driven by density (temperature and moisture) differences between one location and another. Weather differs depending on where somebody is(location) These differences can occur due to the sun angle at any particular spot, which varies by latitude from the tropics. The equator and the area near the equator are closer to the sun, thus it is it is much hotter there. ( sun rays travels shorter distance-more intense heat)

 The elements of weather :

-temperature(hot or cold)

places near the equator(latitude)

mountain tops(altitude)

when the earth rotates, some places are dark, while some are exposed to sunlight. rotation causes different locations to experience different temperatures. 

-rainfall(wet or dry)

the hydrologic cycle, precipitation, the amount of rain received in a place. 

(some places may experience a lot of rainfall,while some places experience a lot of sunlight.)

-wind(air pressure)

movement of air 

wind moves from areas of high pressure to areas of low pressure. 

high pressure: air particles, compact, higher amount of force

low pressure: air particles, far apart, lower amount of force

how do the weather elements affect the way we live:
 -it affects the type of clothes we wear( in singapore, we wear shorts, slippers, tank tops)
-outdoor activities
-perspire
-schooling and work
-natural disasters

Rivers ! :D

The hydrologic cycle:

Evaporation, transpiration, condensation, rainfall, interception, infiltration, surface run-off and groundwater.

Evaporation- when water gains heat and evaporate to water vapour.

Transpiration-water vapour given off by the leaves of plants.

Condensation-water vapour loses heat and condenses to water droplets, the water droplets combine and form clouds

Rainfall-the clouds get too heavy and they fall back to earth.

Interception-flow of water down trees, buildings

Infiltration-water permeates into the ground.

Surface run-off-water flows on the surface into the river, lakes, and seas.

Groundwater-water the seeps into the ground may be absorbed by plants/flow into rivers, lakes and seas.

River source- the beginning of a river channel

Tributaries-small rivers and streams flowing into the main channel.

Confluence- where tributaries join the main river channel

River mouth-the end of the river channel, where the river meets the sea.

The drainage basin is the land area that the river system occupies.

Watershed- the boundary, separating one drainage basin from another.

Meanders- when river erodes sideways and deposits the sediments it is carrying on the opposite banks of the curves.

Floodplains - a flat land where rivers deposit sediments/materials.

Waterfalls-a vertical flow of fast-flowing water, when river flow over a horizontal layer of hard rock overlying soft rock, the soft rock erodes more quickly than the hard rock. Thus, a ledge is formed.

Deltas- layers of sediments that are deposited at the river mouth over a long period of time.

Why don't we feel the Earth moving?

Surprisingly, the Earth actually moves quite fast. It rotates on its axis at about 1.7 km/h and orbits around the Sun at a speed of about 107,000 km/h! So, why is it that we don't feel anything at all, as if the Earth is just a stationary object? 


We do not feel any motion because these speeds are constant. The rotation and orbital speeds of the Earth stay the same and so we do not feel any acceleration or deceleration. You will only feel motion if your speed changes. Have you ever been on an airplane? On my many hated rides on airplanes, when the airplane accelerates and takes off, I feel a lot of motion. However, I realise that once in the air, I feel as though the airplane is not moving at all, as if we were just hovering aimlessly in the sky.


I just decided to share this bit of information with all of you as after Miss J's lesson last week, this question just randomly popped into my head. I found it interesting and this was the result of my research!


Also, do you remember how the plates of the Earth's crusts form volcanoes? If you remember, you may have guessed that volcano eruptions are related to the Earth's second outermost layer, the mantle. 


When rock inside the Earth becomes hot enough it melts. The molten rock(magma) is less dense compared to the surrounding solid rock. The relatively low density of the magma causes it to rise to the surface of the Earth. If the magma contains water and dissolved gases, when the magma reaches the surface, the water and dissolved gases will suddenly expand into steam and gas, causing a violent eruption.


The link below has pictures that will help you understand!

http://library.thinkquest.org/03oct/01550/eruptions.htm

Rocks...Are they what they seem?

Rocks are not just the little things you kick around when you are bored. They are actually very important to us as they form landforms on the Earth. 

  There is a big difference between minerals and rocks. Rocks are groups of different minerals pushed together and combined. The minerals that make up rocks are quartz, sand and etc. The formation of rocks is due to various effects on the Earth. There are THREE types of rocks: Igneous, Sedimentary and Metamorphic.  The video below might help you remember them.

 

Now for the real thing! This next video gives you a deeper understanding of rocks and the rock cycle:D

Questions to ponder...

• What can we look out for when we want to tell if the volcano is about to erupt?
• How is magma made in the Earth's interior?
• If there were no such things as volcanos, causing magma and lava to stay inside the Earth, what would be the affect on Earth and us?

By: Matthea, Natalie and Mildred:)

Here Comes the Sun

Yesterday—Superbowl *Sun*day—NASA released the first global view of our sun, courtesy of a pair of space probes collectively called Solar TErrestrial RElations Observatory, or STEREO.
Launched in October 2006, the two probes left Earth together but then separated and headed for opposite sides of the solar orb.
On February 6, STEREO-A and STEREO-B finally reached opposition, when each spacecraft was aimed at a different hemisphere.
In this configuration, the two probes allowed scientists to simultaneously see both sides of the sun for the first time in human history.

Wonder Twin powers, activate!
—Image courtesy NASA
"This is a big moment in solar physics," STEREO team member Angelos Vourlidas, of the Naval Research Lab in Washington, D.C., said in a NASA statement.
"STEREO has revealed the sun as it really is—a sphere of hot plasma and intricately woven magnetic fields."
The global view is a boon to scientists studying the sun's magnetic activity, such as coronal mass ejections and solar flares, which can fire huge blasts of charged particles toward Earth.
Until now we've had to rely on observatories that can see only the side of the sun facing Earth. It takes the sun about 27 days to complete a full rotation on its axis, so when storms were forming on the far side, they'd have plenty of time to build up and take us by surprise.
"With this nice global model, we can now track solar storms heading toward other planets, too," added STEREO program scientist Lika Guhathakurta. "This is important for NASA missions to Mercury, Mars, asteroids ... you name it."
In addition to the released images, NASA put together a nifty video that illustrates how the STEREO probes work, what they can teach us about the Earth-sun interaction, and what STEREO will get up to as the pair of probes continues to circle back around the sun over the next few years:

By: Mildred, Matthea, Natalie XD

source-http://blogs.nationalgeographic.com/blogs/news/breakingorbit/2011/02/nasa-stereo-entire-sun-video.html