Satellite Watches Mexico City Sink
Mexico City is sinking very fast. New pictures from space show this clearly. Some areas drop more than two centimetres every month. A satellite called NISAR took the pictures. NASA (the US space agency) and India's space agency built it. The worst sinking is near the airport and an old city monument.
Why is this happening? The city was built on an old lake bed. The ground is soft. People pump too much water from below. The soft ground then shrinks. About half of the city's water comes from underground. The water level there is falling fast.
The damage is easy to see. Old churches lean. Pipes break and lose lots of water. About 40 per cent of the water is wasted this way. Scientists want to save buildings. But stopping the sinking is very hard. People still need water every day.
