Volcanic regions such as Iceland, Kenya and the Philippines produce very high-temperature geothermal resources.
High and mid-grade geothermal heat is located along active tectonic fault lines, such as California and the Ring of Fire. The deeper faults provide pathways for the heat to rise closer to the earth's surface.
Heat rising from the earth's core can become captured under a deep blanket of shale, such as the Western Sedimentary Basin. This type of geological phenomenon creates mid-grade geothermal temperatures which can be found in the Clarke Lake reservoir in Northeastern BC and across many countries in Europe.
Radiogenic heat is caused by the decay of naturally occurring radioactive isotopes. This can create low-grade geothermal resources. This can be found in the Canadian Shield and parts of Australia. DEEP in Southern Saskatchewan is an example of a radiogenic heat source.
The geothermal industry continues to advance, as technology progresses it will be easier to access this resource.