The reaction causes a greater energy wave which cracks the planet, yes.
BFG-9000
"The BFG-9000 remains the most powerful weapon ever designed by the UAC., releasing a projectile of pure roiling Argent Plasma. The sphere of superheated energy undulates as Argent Tendriles lash out, drawn to nearby organic material an immediately producing a fatal explosion from within.
Dr. Samuel Hayden recently deployed the weapon to Phobos, where it served as the inspirational linchpin for the development of the BFG-10000 defense station. When mounted inside the station's magnifying array, the BFG can be fired into a series of reactive lensing rings; these rings pump a constant stream of gaseous Argent through the barrel, which ignites in reaction to the electrified plasma, producing a tremendous energy wave powerful enough to crack the surface of a planet."
BFG-10000
"Originally established as a mining and communication relay, the UAC outpost on
Phobos began immediate expansion following the destruction of the Argent facility on Mars. The UAC Board of Directors, intent on retaining their monopoly of the red planet and its surrounding airspace, issued the construction of an expansive defensive platform. Using technology derived from the
BFG-9000, the design plan called for a massive particle cannon to be built on the orbiting moon. The BFG-10000, the largest man-made weapon platform ever conceived, wields enough firepower to defend against even the most sophisticated of capital-grade FTL cruisers in existence - or against the eventual potentiality of a space-bound demonic threat."