I noticed these detailed tree-like river structures in Google Earth
How and why do these form? Rivers don't typically split. What would cause the water to keep branching off again and again, forming these tree-like fractal patterns? I count as many as 7-8 branch splits even in the smaller trees.
I expect the answers will provide qualitative explanations, but if anyone can connect it to quantitative physical models that would be even better (e.g. diffusion limited aggregation, viscous fingering, dielectric breakdown all have analogous mechanisms behind them; could this one be related?)