Let's finish this with a bang.

Dig yourself out of that situation as fast as you can; fly straight out of the ground and and high as you can, hopefully avoiding the first Earthquake. Before it pulls off the next Earthquake, give it a nice solid Blizzard to finish it off. If it still survives, end with Icy Wind.

Dig (back out, quickly to jump out with enough force to keep Florence airborne for a few seconds)~~Blizzard~~Ice Beam