The background noise is fumarola, or volcanic exhalation, which usually occurs on active volcanoes. There are several of them in the Námafjall geothermal area. Gases are released from the fumaroles, mainly sulfur dioxide – which causes the yellow color around the fumaroles – and hydrogen chloride. In addition, water vapor, the temperature of which can reach a thousand degrees Celsius.
Then gurgling is boiling water with silica, which can be described as “mud”. All this is located north of Lake Mývatn, in the vicinity of the Krafla volcano. The terrain of Hverir – that’s what the field is called – looks like another planet. I recorded the sound on a sunny morning, but the moon was still visible in the sky – which is quite normal during the Icelandic winter. I remember looking at it and taking a picture, I thought: “if the moon is there… where am I?”