A landslide is a rapid down slope movement of lose soil and rock. This may occur as a result of a road cutting into a steep slope which may cause regolith above the road to become unstable and fall down slope. Also constant erosion by waves can cause undercutting in cliffs allowing overhanging ledges to collapse as a landslide.
Ring of Fire
The ring of fire also referred to as the circum pacific belt is a path along the Pacific Ocean characterised by active volcanoes and frequent earthquakes. The majority of the earths volcanoes and earthquakes take place along the ring of fire. It is situated along the edge of the pacific plate. Volcanic activity creates mid ocean ridges, volcanic islands and volcanic mountains.
Central business district
The CBD is an area with big banks, office blocks and department stores. The cost of land is very high so buildings are multi storey. In Dublin the CBD stretches from St. Stephen’s Green on the South side of the Liffey to O’Connell Street on the North side of the Liffey.
Evaporation is when the sun heats up water in rivers or lakes or the ocean and turns it into vapour or steam. The water vapour or steam leaves the river, lake or ocean and goes into the air.
As water vaporizes into water vapor, it rises up in the atmosphere. At high altitudes the water vapors changes into very tiny particles of ice /water droplets because of low temperature. This process is called condensation. These particles come close together and form clouds and fogs in the sky.
Precipitation occurs when so much water has condensed that the air cannot hold it anymore. The clouds get heavy and water falls back to the earth in the form of rain, hail, sleet or snow.
Collection: This is when water that falls from the clouds as rain, snow, hail or sleet, collects in the oceans, rivers, lakes, streams. Most will infiltrate (soak into) the ground and will collect as underground water. The water cycle is powered by the sun’s energy and by gravity.
Causes of population change