if you are not familiar with the location, go to an alien abandoned base in the lost river to get the signal location first. On the way to the tree of life, I saw a small skeleton of a sea dragon. Go to the right and there is a shabby building inside. Remember to bring a purple chip. After getting the signal position, go back and replenish to the lava area. The geothermal power plant is in a mountain in the lava area, with an entrance halfway up the mountain, which emits green light. It's recommended to go through the mecha. You need: mecha, advanced pressure compensation module, electric drill arm (mining kyanite and ionic crystal) and fighting arm (easy to move).