It isn’t surprising to know how insignificant-looking smaller changes can ripple through our lives, resulting in huge waves that we might never expect. Just as a tiny shift in the mechanisms of the delicate gears of a clock, probably as slight as a hair’s breadth, can lead to a big change in the correct time of the clock. Similarly, in the grand machinery of our planet, even the smallest changes can have huge impacts.
This comes in light of some new discoveries by NASA on how China’s massive engineering project, the Three Gorges Dam, has affected the Earth’s rotation, resulting in an almost unnoticeable but scientifically significant change.
The Three Gorges Dam in China is one of the greatest marvels ever constructed in history and is currently the largest hydroelectric power station in the world. Constructed on the Yangtze River, this huge structure was finished in 2012 with a reservoir that can hold 39.3 cubic kilometres of water. While the main objective of the dam is to generate renewable energy, its construction has had adverse effects beyond the earth’s surface.
According to NASA, the increasing water pressure behind the dam is also increasing the moment of inertia of the Earth. The moment of inertia amounts to the total resistance against any rotary motion. By increasing this resistance caused by the dam, it reduces the speed at which the Earth rotates a snitch. This would cause the day to be increased by 0.06 microseconds.
How is the microsecond change impactful?
A microsecond is one millionth of a second, thus, a change of 0.06 microseconds may be regarded as nothing to most people. But in the field of astrophysics and planetary science, even changes as small as that really do matter. The variation in Earth’s rotation speed results in various natural changes concerning the duration of the day and night. These will also alter the tides, and by large affect the stability of satellite orbits. Thus, such changes should be known and taken into account for accurate scientific measurements and predictions.
The construction of the dam also has environmental effects
Far from affecting Earth’s rotation, the Three Gorges Dam has also changed the environmental scenario considerably. The construction of the dam has displaced more than 1.2 million people’s homes and has flooded vast areas, including natural habitats and many more sites of historical interest. The change of river flow has affected the local ecosystems because of changing fish populations and water quality. In addition, it also contributes to geological changes such as increased seismic activity in the region.
How is the construction of the dam an example of the ‘butterfly effect’?
Representative Image (Credits: Canva)
The impact of the construction of the Three Gorges Dam is an example of the ‘butterfly effect’ , for the impact on Earth’s rotation. It is a concept from chaos theory that suggests small changes can have large, unpredictable consequences. In this case, the construction of a single dam has led to a measurable change in the planet’s rotational speed, which shows how each activity on this earth is interconnected to one another
As we use natural resources and reshape the environment, it is very important to consider the potential long-term impacts of our actions. However, advancements may be necessary but so is the sustainable use of environmental resources.
