The Spirit of Prophecy used the same code words when you read
any of the books of the Bible. If you do not understand the
tongue of the Spirit of Prophecy you will not fully comprehend
Moses, the Prophets, Christ and his Apostles. Specially for the Apostle John who is a major Prophet, for the Book of
Revelation you definitely need to be able to translate what these two words, "Earth" and "Sea" actually mean.

The Symbolism of the Earth is used for the Land of Israel.

The Symbolism of the Sea is used for Gentiles, Nations.

Make sure to read this Study:

I beheld another beast coming up out of the Earth
https://www.brighteon.com/ab684e18-d196-4be5-a0b7-5c70c11e31d2

That way you will be able to see for yourself how these Symbolism were used by the Prophets and Christ himself, this will provide you with the keys to understand Revelation.

Basically the Seven Trumpets and the Seven Vials are the
response to this request of the souls of the Martyrs:

Revelation 6:
9 And when he had opened the fifth seal, I saw under the altar the souls of them that were slain for the word of God, and for the testimony which they held:
10 And they cried with a loud voice, saying, How long, O Lord, holy and true, dost thou not judge and avenge our blood on them that dwell on the earth?

The Souls of the Prophets and of the Saints of the Early Church which were killed by the religious leaders of the Jews cried to God with a loud voice inquiring when their blood will be avenged on the inhabitants of "the Earth" (the land of Israel).

The souls of the Martyrs were told to rest until more fellow servants of Christ would be killed for their testimony. Afterward, the Sixth seal is opened and a major shake down or shake up is happening in heaven and on the "Earth". Heaven "departed" and the Stars of Heaven fell on the "Earth". Big Clamor in heaven, Satan and 1/3 of the angels are cast down.

Revelation 12:
9 And the great dragon was cast out, that old serpent, called the Devil, and Satan, which deceiveth the whole world: he was cast out into the earth, and his angels were cast out with him.
10 And I heard a loud voice saying in heaven, Now is come salvation, and strength, and the kingdom of our God, and the power of his Christ: for the accuser of our brethren is cast down, which accused them before our God day and night.
11 And they overcame him by the blood of the Lamb, and by the word of their testimony; and they loved not their lives unto the death. Therefore rejoice, ye heavens, and ye that dwell in them. Woe to the inhabiters of the earth and of the sea! for the devil is come down unto you, having great wrath, because he knoweth that he hath but a short time.

The 7 Trumpets are warnings to inhabitants of the land of Israel shedding innocent blood of those having the testimony
of Christ, rebelling against God and not repenting for inviting to be possessed by fallen angels when they killed the Saints. These wicked men also called upon the fallen Angels to protect and cover them against the Wrath of God and of the Lamb.

Rev 12:4
And his tail drew the third part of the stars of heaven, and did cast them to the earth ...

Isaiah 9:15
... the prophet that teacheth lies, he is the tail.

The 1/3 number in 6 of the 7 Trumpets is related to the event
described in the above verses. When these trumpets sounded, one third of demons from the lowest hell are released upon the "Earth". One third of the Light of God and Christ is dimmed. One third of the fountains of water are poisoned with the wormwood of False Teachings and the worship of false gods, etc... (the 7th Trumpet is the final judgment over "the Earth")

After the warnings of each Trumpet, the wrath of God is poured upon those dwelling upon "the Earth". The pouring of a vial is the corresponding judgment of God linked to the relevant Trumpet. One Vial for each Trumpet, 7 Vials for 7 Trumpets.

Prior to the fall of Jerusalem in 70 AD, rivers, lakes, the sea of Galilee and the dead sea were filled with dead men which were killed by the Romans.

Rev 16:
4 And the third angel poured out his vial upon the rivers and fountains of waters; and they became blood.
5 And I heard the angel of the waters say, Thou art righteous, O Lord, which art, and wast, and shalt be, because thou hast judged thus.
6 For they have shed the blood of saints and prophets, and thou hast given them blood to drink; for they are worthy.

After the 7th Vial is poured, if you read the Jewish Historian
Josephus you will find out that Jerusalem was actually divided in 3 parts, and the stones from the Roman Catapults weighted one Talent. And Cities after Cities of the Tribes of Israel fell...

Revelation 16:
19 And the great city was divided into three parts...

21 And there fell upon men a great hail out of heaven, every stone about the weight of a talent...