This is my report writing about a part of the earthquake in Christchurch. I chose to write about the liquefaction that caused. My writing shows the different features of a report writing that has classification,the description and a conclusion.

Here is a image before and after the earthquake

The second earthquake had more liquefaction on the streets of Christchurch making the roads dangerous and not used by cars and vehicles.

Liquefaction is the process where, during earthquake shaking, sand and silt grains in wet soil are rearranged and the water in the spaces between the grains is squeezed.

During an earthquake, liquefied soils can sometimes move sideways, usually towards streams or rivers, but also if the surrounding land is lower than the liquefied land.

Pressure builds up in the water until the silt and sand grains 'float' in the water, and the soil behaves more like a liquid than a solid. For example when you wet sand it looks like mud.   Rivers have layers of silt and sand in many places, especially in low-lying ground near the coast like Christchurch. The top layer of sand can become flat, firm and dry – ideal for building on – but this often hides layers of waterlogged sand  underneath the soil surface.

Liquefaction only happens when water is beneath the ground and when shaking is severe. When the ground becomes liquid, it can no longer support the weight of buildings, so these tend to sink.

It’s like a plunger you use when you are trying to unblock a drain.  The liquid will look for a gap and squeeze it’s way through spraying out through the sides.  When there is pressure on the ground above, this pushes down on the ground and the liquid it squirted out to the top.

Liquefaction has  caused the ground to sink, spread and crack. Underground pipes and tanks float and break. Power poles fall and break cables. Liquefaction is not just a New Zealand problem. During earthquake cars have been swallowed by liquefaction.

There are five reasons why liquefaction happens, it is the strength of ground shaking, how long it shakes for, how deep the quake is to the water table, soil properties (grain size and density), and the pressures.

It is not only a earthquake that cause major damage towns living near the cost well also be damaged by liquefaction