I checked and the collapse of the WTC towers produced magnitude 2.1 and 2.2 quakes, but most of the energy was consumed in pulverizing the concrete and twisting the steel structure.
Given that it's a logarithmic scale, magnitude 3-4 earthquakes are not ruled out of the use of lancets.
I still think the orbital parameters and payload levels mean the lancets are hyper accelerated by a rocket booster and mass less than you think. Velocity is paramount.
I also think that at these speeds we have deep penetration without surface cratering,
Just speculation, of course.