Coral Reefs

What are Corals?
Corals are tiny invertebrate animals that live together in colonies in warm shallow water. The term "invertebrate" means that they have no skeleton.
Corals build structures called reefs from calcium and carbon that they take from the sea water. Corals stay bin one place in the reef they have created for the rest of their lives.
An individual coral is also called a coral polyp.

A coral polyp

Conditions for Coral Reef Survival

Corals need the conditions to be just right in order to survive. Click on the link below to fnd out what conditioons that coral reefs need to survive.

What Do Coral Reefs Need to Survive? 

Click read more to see the threats to coral reefs.

Climate

What is Climate?
The term climate refers to the weather conditions that occur in an area over a long period of time.

There are three types of climate on which we will focus. These are Tropical Continental, Equatorial and Tropical Marine Climate.

Each climate has different characteristics. That is, each climate has features that we can use to say how it is different from other climate types
The climates also have different types of vegetation that grow in the areas that experience the different climates. These types of vegetation have changed in different ways that allow them to survive in the climatic conditions in which they grow.
 
The links below will bring you to a website with the three different types of climate to be explored. 

For each climate make sure you can identify the:

      * characteristics of each climate
      * vegetation present
      * adaptions of vegetation to the climate 

Click each link to view the corresponding climate:
          Tropical Continental Climate
          Equatorial Climate
          Tropical Marine Climate

Six Figure Grid Reference

Grid References 
Maps may be divided into numbered squares. These squares can be used to give a place a four or six-figure grid reference.

Four Figure Grid Reference
Maps have two sets of numbers tha are used for four figure grid reference. The numbers running along the bottom of the map are called eastings because they increase going to the east.
The numbers that fun along the sides of the map are called northings because increase from from south to north. These numbers combined (two eastings and two northings) will give four numbers telling the location of the object. These four numbers are the reason it is called four figure grid reference.

For example the location of the tree on the grid will use the easting (19) and the northing (43) to give the four figure 1943. The coordinates 1943 tells the box in which the tree is located.

For six figure grid reference, we need two more numbers to be more accurate. We can divide the grid into 10 and count the lines to find the two additional numbers. So the four figure coordinates are 1943.
We will leave spaces fpr the two extra numbers we will need for six figure reference like this 19_43_ .
The six figure grid reference for the tree is 196438. The 6 is found by counting along the eastings and the 8 is found by counting along the northings.

Folding

What is folding?
Folding refers to the bending of the earth's crust. The rocks in the earth's crust move and bend because several forces are acting upon them.


The main types of forces involved in the movement of the earth's crust are tension, compression and shearing forces.
Compressional forces push btogether, tensional forces pull apart and shear forces  slide past each other.

Compression is the main force responsible for folding. The diagram below shows how these forces affect the earth's crust.

Notice how compression causes the rock to bend? This is called folding. Click "read more" below to see more about folding.

Rainfall

 Some Key terms.

Precipitation - Any moisture that falls to the ground. For example, rain snow and hail are all forms of precipitation.

Condensation -  The change or conversion of vapour or gas to liquid. In the case of rainfall, water vapour is changed to liquid.

Saturation - the state or process that occurs when no more of something can be absorbed, combined with, or added. In the case of rainfall, when the clouds cannot absorb any more water they are said to be saturated.

Relief rainfall
Relief rainfall occurs when air has been blown over the sea and is then forced up over an area of high land. The air becomes cooler as it rises and condenses to form clouds. As the clouds become saturated, rainfall occurs.

Frontal rainfall
Frontal rainfall occurs when warm air is forced to rise over cold air. The moisture in the warm air condenses as it cools which causes clouds. When the clouds experience saturation, precipitation (rainfall) occurs.

Convectional rainfall
Occurs mostly in tropics where it is hot. The air is heated by the sun and this hot air rises. As the air rises it cools and condenses to form clouds. These clouds become saturated and cause rainfall. If the air is hot enough, it rises very quickly and can cause thunderstorms.