1.3 The sun and the abiotic environment: rocks and soil

Temperature changes associated with the heat of the sun are a major cause of mechanical or physical weathering, which is the breakdown of rocks in situ as a result of different components of rocks heating up and expanding at different rates, or water in cracks and crevices in the rocks freezing during the cooler hours of the night and the rock being broken apart by the expanding ice.

Source 1.4 Black sand beach in Hawaii formed by the erosion of basalt

Source 1.4a The sun affects weather patterns by changing parts of the Earth’s temperature, through heating up the land and water.

Source 1.4b Temperature changes caused by the sun affect factors like humidity and air pressure levels – which have great consequences for an ecosystem.

Source 1.4c Water in cracks and crevices in the rocks freezes, and when the ice expands the rock breaks apart.

Source 1.4d Granular disintegration is directly caused by the Sun. Dark-coloured compounds in rocks will heat up more quickly than lighter compounds

Source 1.4e The dark compounds expand more quickly and can cause small grains of rock to break off the parent rock. This is most evident in a volcanic rock known as granite.