The cap-rock of a geothermal reservoir (or oil and gas reservoir) is the non-porous and impermeable layer that prevents fluid from escaping.
Ko te pātoka o te māpuna waiwhatu (hinu rānei, haurehu rānei) te apa hemahema kore, pōareare kore e aukati ana i te rerenga atu o ngā wai.
Luckily the geothermal system below us maintains its pressure and temperature because the impermeable cap-rock above it keeps the high-pressure fluids contained.
Kua waimarie tātou i te mea mau ai te pēhanga me te paemahana o te pūnaha ngāwhā i raro nei i te tāwhitanga o te pātoka pītongatonga o runga.
