I've just read an article in German about the weak gravity spot in India. The reason is that earth is not as smooth as we (used to) think it is. Apparently there's a spot in the ocean near India where gravity is weaker than average. Naturally, the people that live their must weigh less. But I was wondering how much less? Is there any reliable data? I'm just curious
Google “gravimetric data” and take your pick. It’s a combination of data from satellites (60 plus years) and surface gravimetry using very sensitive instruments in geologically quiet locations.