[The revival had nothing to do with that quake experience.]
The seeds of revival were sown immediately following the earthquake. God moves - His Way, His Time.
Rev. Heath wrote:
“Port Royal was terribly destroyed by an earthquake and breaking in of the sea upon it. The destruction was sudden...in four minutes multitudes were killed by the falling houses...
...I believe God I never in my life saw such a terror...the earth opened and swallowed up people before my face...
The sea swallowed up the greatest part of that wretched sinful place...They are so wicked, I fear God...will utterly destroy all by this dreadful Judgment...
By this terrible judgment, God will make them reform their lives, for there was not a more ungodly people on the face of the earth.”
A resident, Samuel Bernard, wrote:
“We shall be unworthy of God’s mercies if we be not by His judgments taught to learn righteousness.”
150 years later. I don’t think the people were thinking of the old earthquake. Even the youngest survivor was dead 50 years at that point. That’s all I’m saying.
There was a general revival at least continent-wide around that time.
Just incidentally saw this in Wiki...
“the whole island was severely affected by an epidemic of cholera in 1850.”
That may be more likely your spur for revival.