What do we expect God to do in our world? I looked up "quake" in the Oremus bible browser, http://bible.oremus.org. The earth quaked when God helped Deborah and Barak defeat the enemy (Judges 5:1-5), when Jonathan defeated the Philistines (1 Samuel 14:150, and when David was victorious (2 Samuel 22:8-16 and Psalm 18:7).
Can we imagine some other dramatic shake-up than a war battle? Can we pray that a God who accompanied Deborah, Barak, Jonathan, and David will be able to confound our enemies of apathy, greed, selfishness, and fear? Remember that Isaiah was remembering that God has done awesome deeds that had not been expected.
Lectio Divina: Isaiah 64:1; Psalm 80:3