I calculated this feat a long time ago, but I used a panel that came out with lowballed results.
Ikusatsunagi's Size is quite inconsistent, but I believe that this panel should be the most accurate one,
since this panel exists for the sole reason of showing how big Ikusa is.
Fodder = 1.7 meters = 1 px
Ikusa's Height = 1284 px = 1284(1.7/1) = 2182.8 meters ~= 2.1 km
Ikusa's Arm = 892 px = 892(1.7/1) = 1516.4 meters
Iku’s Arm = 1516.4 meters = 52 px
Now to calculate the volume of the slice:
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Truncated rectangular Pyramid , so:
V = 1/3 * H * (1.5 * L *(W1 + W2))
Volume of the flat area[]
The flat area is hardest one to determine, given the inconsistent craters in different panels.
So as a lowball, I’ll calculate it using the crater shown in another panel(It needs to be kept in mind that it expanded after entering the hill area, which might seems a little wonky scaling wise, but should be viable nonetheless)
This is easy to calculate, given that it’s a simple rectangle.
Average Person = 1.7 meters = 13 px
W = 142 px = 142(1.7/13) = 18.56 meters
H = 125 px = 125(1.7/13) = 16.34 meters
L = 238 px = 238(239.7/52) = 1097.08 meters
V1 = W * H * L = 18.56 * 16.34 * 1097.08 = 332711.89 m^3
Volume of the 1st Hill[]
W1 = 114 px = 114(1516.4/52) = 3324.4 meters
W2 = 36 px = 36(1516.4/52) = 1049.8 meters
L = 110 px = 110(1516.4/52) = 3207.7 meters
H = 91 px = 91(1516.4/52) = 2653.7 meters
V2 = 1/3 * H * (1.5 * L *(W1 + W2)) = 1/3 * 2653.7* (1.5 * 3207.7 *(3324.4 + 1049.8)) = 18617193349.9 m^3
Volume of the 2nd Hill[]
L = 136 px = 136(1516.4/52) = 3965.9 meters
W1 = 75 px = 75(1516.4/52) = 2187.1 meters
W2 = 36 px = 36(1516.4/52) = 1049.8 meters
H = 88 px = 88(1516.4/52) = 2566.2 meters
V3 = 1/3 * H * (1.5 * L *(W1 + W2)) = 1/3 * 2566.2 * (1.5 * 3965.9 *(2187.1 + 1049.8)) = 16471439176.101 m^3
Volume of the rocky-flat area[]
I’ll have to substract the 238 px in the beginning of the slash, since it was visibly far smaller than later on, and started growing only after reaching a rocky area.
This will be a slight lowball, since there was still a decent part of the slash that I just won’t calculate due to inconsistent panels(the slash near the soldiers is too small)
L = 926 - 238 - (136 + 114) = 438 px = 438(1516.4/52) = 12772.7 meters
W1 = 45 px = 45(1516.4/52) = 1312.2 meters
W2 = 36 px = 36(1516.4/52) = 1049.8 meters
H = 10 px = 10(1516.4/52) = 291.6 meters
V4 = 1/3 * H * (1.5 * L *(W1 + W2)) = 1/3 * 291.6 * (1.5 * 12772.7 *(1312.2 + 1049.8)) = 4398657316.92 m^3
Conclusion[]
V = V1 + V2 + V3 + V4 = 39487622554.811 m^3
Pulverisation:
E = 39487622554.811 m^3 * 1000000 * 214.35 j/cc = 8464171894623737850 joules = 2.02 gigatons(High 7-A)
EDIT:
I'll be honest, I have no idea if this scaling is more accurate or actually highballed. After hearing some arguments against it, I am neutral on the subject.