It would be impossible for those whom the Lord chose to slay to escape even if they tried to dig into the earth or climb into the sky (cf. Psalm 139:7-8; Jonah 1-2). [source][source][source]
"If neither heights nor depths can separate people from the love of God (cf. Romans 8:38-39), they are also unable to hide them from the wrath of God." [1][source]
The ancients conceived of Sheol as under the surface of the earth, so digging into Sheol meant hiding in the ground. Neither would hiding in the forests and caves of Mt. Carmel, one of the highest elevations in Israel, or trying to conceal oneself on the floor of the sea be effective. The Lord would seek the guilty out and command His agents to execute them, even if that agent had to be a serpent in the sea (cf. Amos 5:19; Job 26:12-13; Psalm 74:13-14; Psalm 89:9-10; Isaiah 27:1; Isaiah 51:9-10). Note the chiastic structure in these verses going from down to up and back down, signifying all places. [source][source][source]