The opening of the first six seals have just portrayed the course of this age leading up to, and including the end of the age and the outpouring of God's final wrath on Satan, Antichrist, and all those who receive their mark and follow in their ways. The stage is now set for the close up view of the events of the Tribulation itself. In other words, the seven trumpets zero in on the events of the sixth seal in Revelation 6:12-17.
As the seventh seal is opened, no specific action of judgment is tied directly to it. The seventh seal contains the seven trumpets. Seven angels appear with seven trumpets - Revelation 8:1-2 - "When the Lamb opened the seventh seal, there was silence in heaven for about half an hour.  Then I saw the seven angels who stand before God, and seven trumpets were given to them." This second series of seven trumpets will reveal an intensification of the climactic events of the end of the age - the great Tribulation itself.