NASA scientists have discovered that China’s massive Three Gorges Dam is doing more than generating electricity — it’s actually slightly slowing the rotation of Earth.

Located in Hubei province, the Three Gorges Dam is the largest hydroelectric power station in the world. Spanning over 2 kilometers across the Yangtze River and standing 185 meters tall, it produces 22,500 megawatts of electricity — more than the power output of many countries.

But according to new research from NASA, the dam’s enormous reservoir is also affecting the planet’s movement.

More to read:
Earth’s days grow 1.35 seconds every 100,000 years

The reservoir holds about 40 billion cubic meters of water. This vast amount of mass, when concentrated in one location, subtly changes how Earth spins. Specifically, by redistributing weight closer to the equator, it has increased the planet’s moment of inertia — essentially making it slightly harder for Earth to spin, like a figure skater extending their arms.