> a cold, round anomaly about 200 km below the surface.
> By estimating how far the drip had fallen and calculating the speed of its descent, the researchers estimate that the drip broke off between 2 and 5 million years ago.
A few megayears later, the bit that broke off is still falling.
200km in 2m years, I make that in the ballpark of 0.1m per year - a bit less if it's > 2m years, and started below the surface.
alt Hacker News
And the speed at which it happens:
> a cold, round anomaly about 200 km below the surface.
> By estimating how far the drip had fallen and calculating the speed of its descent, the researchers estimate that the drip broke off between 2 and 5 million years ago.
A few megayears later, the bit that broke off is still falling.
200km in 2m years, I make that in the ballpark of 0.1m per year - a bit less if it's > 2m years, and started below the surface.