Terron was forced to move away due to the earth mana within him attracting the earth eaters. However, Walker found it easy to fly over the ground and just avoid stepping anywhere. Niot that he worried they would go after him, he just wanted to make sure that he got a good look at the statue dragon's remains and potential magic it used to trap the earth eaters within a cave.
He was also sensing a surprising amount of water mana for a place that was a dried up riverbed. Just looking, he could see some of the fine sands which had sat there between smoothed stones for years. Yet Walker knew that they were not holding water at all.
The water mana was coming from around the cave, through the walls. With Walker's mana sense, he could tell that it was there but not moving at all. Nor was it some sort of river, stream, or underground lake that was just there all around the cavern.