Hi-res: 800x800
Mathematica code:
Graphics[
Table[
{Thickness[.005],
Circle[{80*Cos[i*Pi/4], 80*Sin[i*Pi/4]},
.5 + (100 - n) (1 + Sign[100 - n])/2]}, {n, 0, 100, 1},
{i, 0, 7, 1}],
PlotRange -> 30, ImageSize -> 800]
Suffice it to say, tumblr is one of the last places I expected to run into Mathematica.