NCEES Principles and Practice of Surveying Practice Exam

Which term best describes the state of land sinking, especially after resource extraction?

1. Erosion

2. Subsidence

3. Reliction

4. Accretion

The correct answer is: Subsidence

The term that best describes the phenomenon of land sinking, particularly after resource extraction, is subsidence. This process occurs when there is a downward movement of the Earth's surface due to various factors, including the removal of natural resources like water, oil, or gas. When these resources are extracted, the support that they provided to the land above may be diminished, leading to a gradual sinking or settling of the ground. Subsidence can have significant implications for the surrounding environment, infrastructure, and ecosystems, as it may result in the formation of sinkholes, changes in groundwater levels, and potential damage to buildings and roads. This occurrence is often monitored and managed to mitigate its impacts, especially in areas prone to resource extraction activities. In contrast, erosion pertains to the wearing away of the Earth's surface, usually caused by wind, water, or ice, leading to the transport of soil and rock. Reliction refers to the gradual recession of water, leaving land exposed, while accretion is the process of land formation through the accumulation of sediment. Thus, the specific context of land sinking directly due to resource activities makes subsidence the correct terminology to use in this scenario.