Revelation 8 – What is this that is described as "something like a great mountain burning?"

Rev 8:8
And the second angel sounded, and something like a great mountain burning with fire was thrown into the sea; and a third of the sea became blood;

Rev 8:9
and a third of the creatures, which were in the sea and had life, died; and a third of the ships were destroyed.

What is this that is described as "something like a great mountain burning?"

Babylon was described as a "destroying mountain" which "destroys the whole earth. "After Babylon was prophesied as being destroyed, they would be "a burnt out mountain."

Jer 51:25 “Behold, I am against you, O destroying mountain, Who destroys the whole earth,” declares the LORD, “And I will stretch out My hand against you, And roll you down from the crags And I will make you a burnt out mountain.

Mountains in Scripture are often metaphorically used to describe kingdoms. The mountain being described here is the Roman Empire. It was "thrown into the sea." The "waters" is a description of the multitudes (or nations) and it is used to describe the many peoples and nations in reference to the Roman Empire.

Rev 17:15 And he said to me, “The waters which you saw where the harlot sits, are peoples and multitudes and nations and tongues.

While the Roman Empire was a very flawed and destructive empire, it did bring law and authority and judgment upon those who broke the laws of Rome. The "ships" are prideful and lofty men.

Isaiah 2:15-17 Against every high tower, Against every fortified wall, 16Against all the ships of Tarshish, And against all the beautiful craft. 17And the pride of man will be humbled, And the loftiness of men will be abased, And the LORD alone will be exalted in that day.

Isaiah 43:14-16 Thus says the LORD your Redeemer, the Holy One of Israel, “For your sake I have sent to Babylon, And will bring them all down as fugitives, Even the Chaldeans, into the ships in which they rejoice. 15“I am the LORD, your Holy One, The Creator of Israel, our King.” 16Thus says the LORD, Who makes a way through the sea And a path through the mighty waters,
At this point let's assume this passage is referring to the Roman Empire. Let's look at this passage once again.

Rev 8:8-9 And the second angel sounded, and something like a great mountain burning with fire was thrown into the sea; and a third of the sea became blood; 9and a third of the creatures, which were in the sea and had life, died; and a third of the ships were destroyed.

If that is the case, then the symbolism of the passage is saying that the Roman Empire took over the people and brought law and order to many who were otherwise lawless, barbaric, and prideful people (referred to as trees, grass, and ships). Rome destroyed many people and controlled the world and gave absolute power to the state.