The sixth seal contains apocalyptic imagery drawn from the whole canon of the prophets. In fact, the sixth seal seems to be a combination of all the stock imagery found in the Old Testament, Second Temple apocalyptic literature, even Greco-Roman imagery of disaster. This does not necessarily mean John used other apocalypses, however. Just as John drew on the Hebrew Bible for this apocalyptic imagery, so too did other Jewish apocalyptic literature.
The apocalyptic elements in the sixth deal (earthquakes, mountains melting, the sun and moon growing dark, etc.) are “stock apocalyptic images.” Just a few examples: Haggai 2:21-22 the Lord will “shake the heavens and the earth.” In Joel 2:10 the earth and sky trembles and the sun, moon and stars no longer shine. In Isaiah 24:18-23 the earth reels like a drunkard and splits apart. Amos 8:9 describes the day of the Lord as “a day of darkness and gloom.” These examples can be easily multiplied in the Hebrew Bible and are found throughout the apocalyptic literature of the Second Temple Period (2 Apoc. Bar. 27; 4 Ezra 4:52-5:13; 6:20-24). For example:
T. Mos. 10:5-6 The sun will not give light. And in darkness the horns of the moon will flee. Yea, they will be broken in pieces. It will be turned wholly into blood. Yea, even the circles of the stars will be thrown into disarray.
Sib. Or. 8.231–238 A lament will rise from all and gnashing of teeth. The light of the sun will be eclipsed and the troupes of stars. He will roll up heaven. The light of the moon will perish. He will elevate ravines, and destroy the heights of hills. No longer will mournful height appear among men. Mountains will be equal to plains, and all the sea will no longer bear voyage. For earth will then be parched with its springs. Bubbling rivers will fail.
Even the Romans considered these types of things to be signs of impending doom. David Aune cites Lactantius’s Epitome 71 (Revelation 2:414, compare to Tacitus, Hist. 1.3.3):
Lactantius Epitome 71 To these plagues will be added also miraculous signs [prodigia] from heaven, that everything may combine to increase human alarm. Comets will frequently be seen. The sun will be darkened with perpetual gloom; the moon will be dyed in blood, nor will it renew its lost light; all the stars will fall, nor will the seasons observe their proper course, for winter and summer will be confounded.
In Rev 6:17, all of the people of the earth who are afflicted by these plagues attempt to hide themselves in the rocks and caves because the “great day of God’s wrath” has come. The reaction is similar to several Old Testament passages, such as Isaiah 2:19-21. But even this reaction is found in other apocalypses. For example:
Sib. Or. 3.601–607 Therefore the Immortal will inflict on all mortals disaster and famine and woes and groans and war and pestilence and lamentable ills, because they were not willing to piously honor the immortal begetter of all men, but honored idols made by hand, revering them, which mortals themselves will cast away, hiding them in clefts of rocks.
What should we make of this parallel material? Is this “revelation or research”? Or, is this like the throne room scene in that John uses the sort of language for the “great and dreadful day of the Lord” that would be expected by Jewish readers (drawn from the Hebrew Bible) and even the Greco-Roman world (drawn from the prodigia)? More difficult, how literal are these stock apocalyptic images? Perhaps John’s point here is to simply describe the standard cosmic catastrophe in terms that everyone in the first century would understand. To say that God is going to judge the world and not use this sort of language would have made little sense to his original readers.
The whole point is to strike terror into the readers because the “great and dreadful day” has come. It is not really necessary to worry over what sorts of natural disasters John is witnessing in his vision, and it is especially not appropriate to declare some modern even “fulfills” this seal. John’s point is that Wrath of the Lamb of God is fearsome indeed!