Buildings in Iceland are heated in this way from the country's many geothermal sites.

Although geothermal sites are capable of providing heat for many decades, individual wells may cool down or run out of water.

In a December 2011 report, India identified six most promising geothermal sites for the development of geothermal energy.

So one possibility is that life may have started at geothermal sites, or adjacent to them or underground, where it was protected.

That's why discoveries of contemporary geothermal sites in the sea are so important.

We spent the past week in Rotorua, a North Island city famous for adventure sports and stinky geothermal sites.

There is also considerable interest in the potential for the use of geothermal sites in the region for the production of electricity.

At least 16 geothermal sites have been identified in British Columbia, Mount Cayley being one of the six areas most capable for commercial development.

The moss species Campylopus pyriformis is restricted to geothermal sites.

This indicates that the area around Meager is a major geothermal site.