Most northerly active geyser field

The Hveravellir geothermal field is located in a shallow valley in Reykjahverfi, northern Iceland, at a latitude of 65.9° N, some 18 km (11 mi) south of the town of Húsavík. In the 1970s, many of the hot springs here were covered over by concrete in order to harness the heat energy for local homes, but a few features remain exposed. These include Ystihver ("northernmost hot spring") which has a 10-m-wide (33-ft) sinter cone and in the past had eruptions that could reach 25 m (82 ft) tall and last up to a minute, though both its potency and frequency are much reduced since boreholes were drilled in its vicinity.

Larger-than-usual eruptions can still be generated from Ystihver with the help of a little soap being added to the water in its basin. When this experiment was conducted in July 2004, the eruption column reached about 10 m (33-ft) high.

At the other side of the world, the most southerly active geyser field is Ōrākei Kōrako, New Zealand’s most concentrated area of geyser activity, located at a latitude of 38.4° S, some 35 km (22 mi) south-west of the city of Rotorua.