= Solution
Interpret “reach” first as remaining an energetic, supersonic <blast wave>, rather than as the arrival of any <acoustic wave>. An <atmospheric blast-wave range> estimate must account for the thin atmosphere: the distance $D=8.5\times10^6\ \mathrm m$ is much greater than its height $H=10^4\ \mathrm m$.
For an optimistic estimate, suppose the deposited <energy> $E$ remains in a horizontally expanding atmospheric layer. If its representative <mass density> is $\rho_a$, the swept mass is of order $\pi D^2H\rho_a$. <Conservation of energy> gives the <self-similar blast wave> scaling
$$
E\sim\pi\rho_aHD^2U^2,\qquad
U(D)\sim\left(\frac E{\pi\rho_aHD^2}\right)^{1/2}.
$$
Using ordinary atmospheric estimates $\rho_a\sim1\ \mathrm{kg\,m^{-3}}$ and <speed of sound> $c_a\sim300\ \mathrm{m\,s^{-1}}$, this gives
$$
\pi D^2H\rho_a\simeq2.3\times10^{18}\ \mathrm{kg},\qquad
U(D)\sim66\ \mathrm{m\,s^{-1}},\qquad U/c_a\sim0.22.
$$
These are scaling estimates, not an exact <shock wave> solution. The strong <shock wave> approximation would already have failed at
$$
D_s\sim\sqrt{\frac E{\pi\rho_aHc_a^2}}\simeq1.9\times10^6\ \mathrm m.
$$
Equivalently, keeping the disturbance strongly supersonic out to $D$ would require substantially more than the sonic-transition <energy> scale
$$
E_s\sim\pi\rho_aHD^2c_a^2\simeq2.0\times10^{23}\ \mathrm J,
$$
which exceeds $10^{22}\ \mathrm J$ by about a factor of twenty. Reasonable atmospheric averages and order-unity geometrical coefficients do not reverse the comparison. Escape of <energy> through the top of the atmosphere makes the fully confined estimate optimistic; <Earth>'s curvature changes its area estimate by an order-unity factor.
\b[The strong atmospheric blast will not survive to Lansing in this model.] A weakened <acoustic wave> can nevertheless travel there. The supplied <energy> and atmospheric height do not determine its detectable amplitude, detailed attenuation or damage: those require an atmospheric propagation model. Thus “no disturbance of any kind reaches Lansing” would be an unjustified stronger conclusion.
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