“These will lift up their voice.” This verse has engendered much scholarly discussion but little certainty, especially since the unspecified “they” is emphasized in the Hebrew text. From the general scope of Scripture, it seems the ones who are shouting for joy are those who have escaped destruction, and/or are peoples that live far away from the destruction. In any case, the ones who suffer destruction are not the ones shouting for joy. This is one of the many verses of Scripture in which the subject of the context abruptly changes, and in this case those who experience God’s deliverance are joyful.
“west.” The Hebrew is literally, the “sea,” that is, the “Western Sea,” the Mediterranean Sea.