Green’s Dictionary of Slang

a strong alcoholic drink.

1869		‘Mark Twain’ Innocents Abroad 149: The uneducated foreigner could not even furnish a Santa Cruz Punch, an Eye-Opener, a Stone-Fence, or an Earthquake.
a.1889		in Chicago Trib. n.p.: Bottled earthquakes are just as bad as the other kind. Scratch a bottled earthquake and you’ll find a cocktail [B&L].
1890–1904		Farmer & Henley Sl. and Its Analogues II 351/1: Bottled earthquake subs. phr. (American) – Intoxicating drink.