And the second angel sounded, and as it were a great mountain burning with fire was cast into the sea: and the third part of the sea became blood; (Revelation 8:8)
The sea, with the life in it and upon it, is shown as the special object of this judgment (cf. ch. 16:3).
The catastrophe announced by the second trumpet has been seen as describing the depredations of the Vandals. Driven from their settlements in Thrace by the incursions of the Huns from Central Asia, the Vandals migrated through Gaul (now France) and Spain into Roman North Africa and established a kingdom centering around Carthage. From there they dominated the western Mediterranean with a navy of pirates, pillaging the coasts of Spain, Italy, and even Greece, and preying upon Roman shipping. The high point of their depredations came in A.D. 455, when for two weeks they looted and pillaged the city of Rome.
This judgment is reminiscent of the first plague in Egypt (Ex. 7:20). In the second plague (Rev. 16:3) the sea “became as the blood of a dead man.”“Blood” here doubtless implies wholesale human slaughter.
As it were.
John apparently finds in a burning mountain the closest representation of the scene that takes place before his eyes. The figure of “burning mountains” occurs in Jewish apocalyptic literature (see Enoch 18:13; R. H. Charles, The Apocrypha and Pseudepigrapha of the Old Testament, vol. 2, p. 200), but there is no evidence that John derived from that source his description of the phenomenon he now sees. Compare Jer. 51:25, where the prophet describes Babylon as a “destroying mountain” that will be made a “burnt mountain.”