This is the great day of the wrath of God, against all of those who rejected his son and persecute his followers
(Note. Seal is a period; the 7 trumpets and the 7 plagues are facts within a period) = (6th and 7th Seal) The 7th Seal , only opens the 7 trumpets= (and in the last trumpet, the dead will revive). (1st. Cor. 15 -52).
(The 7 plagues is the grail of the wrath of God)
We just have to read what God is going to do with the land and the sea of this world, that people trust and get involved, and forget God, thinking that is going to last forever. Today more value is given to preservation of nature (wrong word, it isn’t natural), they say this to deny Gods’ creation. Meanwhile are worried about saving whales, penguins, and other animals in danger of extinction and other things in the world, they are forgetting of the most important, that is to preserve and to save his soul, is the only reason of God creating all this things, and God will demonstrate this at the end. Just an example from 2nd Plague- Rev.16:

3- And the second angel poured out his vial upon the sea; and it became as the blood of a dead [man]: and every living soul died in the sea.
God will ask for accounts, for those of Babylon religion and its followers, (fake Christians that try to fool the people with lies. Rev.16 to 18)- all of them are within the period of the 6th Seal, that is the period of the great ruling leader and his defeat. If someone wants to change his life and accept the Christ, do it before the plagues, because at the time of the plague, there will be no regrets, instead, heat and blasphemy against God of Heaven, as it was after Noah entered the ark and closed the door, and confirms in 4th, 5th and 7th plague, he’ll dump all seven chalices of anger and resentment against those who didn’t repent and accepted his kingdom. Jesus guarantees this in Matthew 24:
14- And this gospel of the kingdom shall be preached in all the world for a witness unto all nations; and then shall the end come.