Uplift refers to the rising of portions of the Earth’s surface while sinking of land refers to the downward shift of portions of Earth’s surface. Both uplift and sinking can be due to plate tectonic movements, including mountain building, or the gravitational adjustment of the Earth’s crust after material has been removed (resulting in uplift) or added (resulting in sinking) such as ice or sediment. The sinking of land can also result from human activities, such as ground water removal or mining, as well as from the melting of permafrost. Both the uplift and sinking of land can be associated with earthquakes.
Sinking of land (subsidence) has occurred due to groundwater removal in the Central Valley of California. The signs on the pole show approximate altitude of the land in 1925, 1955, and 1977 (when the photo was taken). Credit: USGS
Uplift of land affects the Earth system in variety of ways, including:
- Over millions of years sustained uplift due to tectonic process can lead to mountain building, such as the Himalayas. See mountain building for how mountain building can affect the Earth system.
Sinking of land affects the Earth system in variety of ways, including:
- The amount of ground water aquifers can hold if subsidence is caused by ground water extraction and rock layers compact.
- Causing changes in relative sea level rise, which can flood urban areas and impact freshwater and soil quality, and in turn agricultural activities.
Can you think of additional cause and effect relationships between the uplift and sinking of land and other parts of the Earth system?
Visit the mountain building, rock cycle, and weathering pages to learn more about how geologic processes and phenomena affect global climate and ecosystems.