“The first angel sounded: And hail and fire followed, mingled with blood, and they were thrown to the earth. And a third of the trees were burned up, and all green grass was burned up. Then 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. And a third of the living creatures in the sea died, and a third of the ships were destroyed. Then the third angel sounded: And a great star fell from heaven, burning like a torch, and it fell on a third of the rivers and on the springs of water. The name of the star is Wormwood. A third of the waters became wormwood, and many men died from the water, because it was made bitter. Then the fourth angel sounded: And a third of the sun was struck, a third of the moon, and a third of the stars, so that a third of them were darkened. A third of the day did not shine, and likewise the night. And I looked, and I heard an angel flying through the midst of heaven, saying with a loud voice, “Woe, woe, woe to the inhabitants of the earth, because of the remaining blasts of the trumpet of the three angels who are about to sound!“
The remainder of chapter 8 gives us the first four trumpet judgments. The first four trumpet judgments fall on creation, and the last three on humanity.
8:7
The first angel sounded: And hail and fire followed, mingled with blood, and they were thrown to the earth. And a third of the trees were burned up, and all green grass was burned up.
The first trumpet sounds, then one-third of the trees and all green grass on the earth burn up. This event is a judgment of great magnitude on vegetation.
8:8
Then 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.
The second angel sounded his trumpet (vv. 8-9). Something, like a massive burning mountain, was thrown into the sea. Some scientists make ominous predictions of asteroids hitting the earth; they say the impact will be like many hydrogen bombs, causing massive death within hundreds of miles of their collision. According to NASA scientists, an asteroid four kilometers broad could wipe out half the world’s population.
8:9
And a third of the living creatures in the sea died, and a third of the ships were destroyed.
Tidal waves will do further damage. The shock waves of this mountain-like ball of fire will destroy one-third of all the sea creatures and ships on the sea.
8:10
Then the third angel sounded: And a great star fell from heaven, burning like a torch, and it fell on a third of the rivers and on the springs of water.
The third trumpet brings another object from the skies into the earth’s atmosphere and biosphere. It lights up like a torch as it hits the earth’s atmosphere. This third trumpet destroys one-third of the rivers and springs of water. Evidently, this catastrophe is worldwide. This judgment destroys the freshwater supply of much of the earth.
8:11
The name of the star is Wormwood. A third of the waters became wormwood, and many men died from the water, because it was made bitter.
“Wormwood” in Palestine had a bitter taste. The “wormwood” desert plant of Palestine is not poisonous, but the Wormwood here caused men to die.
8:12
Then the fourth angel sounded: And a third of the sun was struck, a third of the moon, and a third of the stars, so that a third of them were darkened. A third of the day did not shine, and likewise the night.
The fourth trumpet affects the sun, moon, and stars. This judgment darkened one-third of them both day and night. This judgment might designate an eclipse.
“Immediately after the tribulation of those days the sun will be darkened, and the moon will not give its light; the stars will fall from heaven, and the powers of the heavens will be shaken. Then the sign of the Son of Man will appear in heaven, and then all the tribes of the earth will mourn, and they will see the Son of Man coming on the clouds of heaven with power and great glory. And He will send His angels with a great sound of a trumpet, and they will gather together His elect from the four winds, from one end of heaven to the other” (Matthew 24:29-31).
8:13
And I looked, and I heard an angel flying through the midst of heaven, saying with a loud voice, “Woe, woe, woe to the inhabitants of the earth, because of the remaining blasts of the trumpet of the three angels who are about to sound
The three-fold repetition of the word “woe” indicates that the remaining three trumpets are even more ominous than the first four. A new and greater level of judgment is about to unfold. This woe is a solemn warning.
Principle:
Sin brings bitterness.
Application:
The book of Revelation gives us a preview of prophetic events. The evil in the world today will pale in light of coming judgment. This event implies that the world will not improve with modernization. It is not getting better and better. We have more conveniences, bells and whistles, and gadgets in our cars than fifty years ago. However, the corrupt nature of man at the beginning of creation is worsening. We have more murder and immorality. This degradation will continue to future prophetic events.
“But evil men and impostors will grow worse and worse, deceiving and being deceived” (2 Timothy 3:13).
Human beings rationalize away the idea of a future catastrophic judgment. We will do anything to stop thinking about the implications of a holy God. We do not want to deal with the consequences of sin. We avoid facing our fears.
The judgments in the above passage chill our blood, as they should. Many who go through tragedy rearrange their values. They put greater emphasis on the things of greater value. As C. S. Lewis said, God uses pain as a megaphone to get the attention of morally deaf people.

could you please explain if there is a difference between Rev.8:7 and 9:4……verse 8 says grass is already burned up or am I just missing something?
Thanks,
P.S I certainly like your verse by verse study!!!
Don, thank you for your words of encouragement.
Re difference between Rev 8:7 and 9:4. There was a passage of time between the two events and the grass may have grown back. χόρτος is the same word in both verses.
Is there a significance to the continued usage of a third of the earth or the moon or the stars as the angels blow trumpets
Wesley, my guess is that the continued usage of “third” carries the idea of progression.