This judgment, the third woe, is an unusual one. It speaks of a time, immediately after the last of the seven trumpets is blown, that a declaration of victory is made. By this point in the Tribulation Jesus has officially won His battle against Satan for ownership of the Earth and He's letting everyone know it. This is expressed clearly in chapter 11, verse 15 where great voices in Heaven declare, "The kingdoms of this world are become the kingdoms of our Lord, and of his Christ; and he shall reign for ever and ever."
So this is more of a victory celebration than a judgment. But even so this is still a judgment, but not against the whole Earth. This one is aimed squarely and specifically against the unsaved as well as Satan and his entire hoard. This is then followed by lightning, big booming voices, lots of insane, loud, crazy thunder (or thunder like sounds), an earthquake (size and area of effect unknown), and great hail. This now closes the period of the trumpet judgments, and it also transfers, at least legally, full ownership of this planet back to God.
Obviously it's always belonged to Him, but legal authority over the planet was given to Adam for a time, which he then transferred to Satan when he sinned and now, due to these three woes and the other judgments before it, legal ownership has now been returned fully to God again. This also signals the halfway point of the Tribulation. The first three and a half years, a very busy period in human history, is now completed. Next comes the death and resurrection of the AntiChrist, his possession by Satan, the desecration of the temple, and the dawning of the Great Tribulation, the last half of Daniel's 70th week, collectively known as "The Tribulation" or "The Great and Terrible Day of the Lord".
(*Do you have a better description, or did you find an error? Please let me know.