Overview
About Gunnuhver Geothermal Area
Heat in a coastal volcanic landscape
Gunnuhver belongs to the Reykjanes geothermal area, where the plate boundary of the offshore Reykjanes Ridge reaches land. Iceland GeoSurvey describes the mud pools below Kísilhóll, or Silica Hill, within a wider landscape of lava, tuff ridges and geothermal seawater. Electrical measurements show that the underground system extends beyond its visible surface features and beneath the sea. The springs therefore reveal only part of a larger geological system; the limits of the steaming ground do not define the whole reservoir.
How the mud forms
Steam rising from boiling reservoir water condenses near the surface and mixes with surface water. Gases travelling with it, including hydrogen sulphide and carbon dioxide, make the mixture acidic. Chemical alteration then changes fresh lava rock into clay, producing the material in the mud pools. Gunnuhver's mud is consequently part of the transformation of the ground itself. Steam vents and pools expose different expressions of the same geothermal activity.
A changing field
Reykjanes Geopark records that part of the present cluster developed after an earthquake swarm in 1967. Activity increased again in 2006, expanding the affected area and damaging a road and viewing platforms. Visit Reykjanes links increased steaming that year to reduced reservoir pressure after geothermal production began. These changes show why a mud pool's dimensions, a vent's position or an old photograph should not be treated as a permanent description of the site.
Gunna's ghost
In a local tale retold by Visit Reykjanes, Gunna is Guðrún Önundardóttir, a woman whose landlord takes her cooking pot when she cannot pay rent. After her death, disturbances and the landlord's death are attributed to her returning spirit. The frightened community seeks a pastor's help. He uses a ball of yarn to draw the ghost towards a hot spring and trap her there. The destination authority preserves different endings: in one, she falls into the spring; in another, she remains bound to the yarn and circles its rim. The narrative explains the place-name through a ghost's confinement. Its accusations, deaths and supernatural events belong to the recorded legend, rather than an established account of what happened at Gunnuhver.
Viewing the geothermal ground
Boardwalk viewpoints provide a way to observe the springs while staying on designated surfaces. Visit Reykjanes instructs visitors to keep to marked paths: Gunnuhver's water and mud are too hot for bathing or touching. Viewing infrastructure is part of how this active landscape is managed, and its presence should not be read as an invitation to approach vents across unmarked ground.
Article reviewed .