Second Blog

Rock Decay

 Rock Decay:

Abha’s weather is changing from being hot to cold but mostly cold , therefore weathering consequences can occur. Many processes shape earth’s surface, one of the important processes is weathering. It is the beginning of changing the earth’s surface, and it occurs over, relatively, large periods of time. It is important to understand the difference between weathering and erosion. Weathering is rock decay, while erosion is the process of transporting weathered material. Weathering and similar processes are studied in the field of geomorphology, which is a combination between both Geography and Geology.

Weathering:

Chemical Decay

There are two different types of weathering. The first type is physical weathering, which can happen in many forms. Physical weathering takes advantage of physical weaknesses in a rock, and increases their numbers. For example, frost decay is one of the important physical weathering processes. It happens more prevalently in high altitudes and latitudes where many freeze-thaw cycles happen. It happens when water seeps into joints, freezes, thermally expands, and melts back. This happens over large periods of time, and after a sufficient number of cycles, blocks of rocks will be pushed away. The second type is chemical decay is the chemical alteration of rocks and minerals. One of the most important chemical decay processes is dissolution. In this process, a mineral is completely dissolved by water. This causes many constructional problems. Sink holes happen when limestone dissolves by groundwater, which makes it important for people to study the layers underneath where they want to build.

 Mass Wasting:

Mass Wasting

Since Abha is above the sea level, it is surrounded by mountains. Mass wasting depends primarily on gravity to transport decayed material down slopes. The material that is being transported is called colluvium. It is important to understand mass wasting in order to mitigate its hazards. Many people lose their houses due to mass wasting. Mass wasting can happen in many forms. Rocks can fall, slide, topple, or flow.