GRACE is the Gravity Recovery and Climate Experiment and it's a two-satellite machine. These two satellites are following each other around in orbit around the earth and instead of looking downward like most earth-orbiting satellites do, these satellites are actually looking each other and measuring the distance between the two satellites.

 

The datum reveals a serious problem in northern India.

 

India is a hot hot spot on the trend map. It’s a well constrained signal that's extremely strong and in this case negative. So it's one that really caught our attention.

 

And subtracting relevant signals, the water table here averaged a 6-meter drop.

 

Over the course the 6-year time series, you can see that we go from a lot of blues to yellows to eventually a situation where it's mostly red and that shows us approximately where these groundwater source declines have occurred.

 

India is a very populated region. 20% of the entire population of the world is residing in India, and only 4% of the water source on earth is in India.