geisotherm
/ˈdʒiːθərm/Definitions
1. noun
a region of the Earth’s crust where geothermal activity occurs
“The geotherm in the area made it an ideal location for a geothermal power plant.”
2. noun
a scale or map of geothermal activity in the Earth’s crust
“The geothermologists created a geotherm to predict areas of high volcanic activity.”