I may be off base here, but it appears that for the shock wave to eject material that high into the stratosphere, the shockwave would already have obliterated the city in the foreground.
The EMP would start the damage; also anything flammable exposed to the flash would ignite.
Even the 100 meter object that produced the Meteor Crater in Arizona (the author uses a representation of that crater in another impact work in the original article), if it bullseyed a city, would leave just a 3/4 mile crater, but would knock down everything for many miles, cause direct damage beyond that, and ejecta would cause damage for miles beyond that.
patience, patience, patience.....
It will be just a few more milliseconds. The city and the observer will be no more