With 180 liters per second of boiling hot water, the world’s most powerful hot spring, Deildartunguhver, does stick out in the West of Iceland.
The water is utilized for a spa called Krauma. As for other spa sites in Iceland, the location is easy to explain according to the forces underneath creating them.
Information about Krauma is found here:
https://krauma.is/en/?gclid=EAIaIQobChMInbbrzr7q5AIVxI2yCh2jaQYCEAAYASAAEgIgtPD_BwE
One of the famous hot springs where people can take a bath is at Landmannalaugar. It is found in the middle of a polygon, with Hekla and Laki at each side.
Landmannalaugar are found at 64°N, the same parallel as Hekla and Laki. The latitude is also the central axis of the SISZ, extending from Hveragerði to Hekla. Repeatedly, we can trace the NS and EW-axis of different polygons. The ductile part of the tectonic plate, reaching 120 km down where convection of mantle starts to take place, gives way to the tectonic drift and breaks along the middle axis from one corner of the polygon to the other. Therefore this is repeatedly seen on the surface.
https://www.fi.is/en/mountain-huts/landmannalaugar
The Reykjanes Ridge can be extended over Iceland (red line), explaining the location of several geothermal spa sites in Iceland.
The red line shows the Reykjanes Ridge and how the two relevant convection rolls extend over iceland. Over the division line, or close to it, the Blue Lagoon at Svartsengi, Krauma of Deildartunga, and Geosea of Skjálfandi Bay, near Húsavík are found.
The blue line is actually the main division line of the two large convection rolls in lower mantle, but the upper most small convection rolls converge against each other. The division line marks the eastern edge of the West Volcanic Zone, where Fontana at Laugarvatn is located, and Nature Baths of Mývatn. It is also close to the Geysir area and Hveravellir in the center of Iceland. The Reykjadalur geothermal river has many bathing sites, near Hveragerði, which is of course on the blue line. Therefore, some additional points could be added with explanations according to the mantle currents pattern underneath. It is not necessary, though, because this shows the main pattern.
This shows the resemblance between convection rolls of the mantle and the main geothermal spa areas in Iceland.
Here is a list of web sites for those spa sites.
Krauma – at Deildartunga in Borgarfjörður area, West Iceland:
https://krauma.is/en/?gclid=EAIaIQobChMI8vrIhr_T5AIVRcjeCh249AJqEAAYASAAEgJZ6fD_BwE
Geosea – at Húsavík í NE Iceland:
https://www.geosea.is/en?gclid=EAIaIQobChMI5ZLLrL_T5AIV0-d3Ch0ulwU2EAAYASAAEgJWwfD_BwE
Fontana – at Laugarvatn, South Iceland:
Blue Lagoon – at Svartsengi on the Reykjanes Peninsula:
Nature Baths – at Mývatn in NE Iceland:
Reykjadalur River – at Hveragerði in Ölfus district, South Iceland:
https://www.biteoficeland.com/reykjadalur-hot-springs-valley-iceland/
Hveravellir – NE of Langjökull in Central Iceland
The Blue Lagoon in Iceland is close to the Reykjanes Ridge which divides the Eurasian tectonic plate from the North American tectonic plate. Shown in context with the mantle currents, the exact location is on the top of a perpendicular division line.
Besides this, the Reykjanes Ridge actually ends close tho the Reykjanes Peninsula, and a volcanic zone replaces its role as a divisional feature between the tectonic plates. The Blue Lagoon is found within that volcanic zone, explaining the location further. Zooming in and adding the tectonic division line shows how accurate the crossings fit with the location of the Blue Lagoon:
The tectonic featueres consist mainly of NE trending volcanic fissures and N-S oriented earthquake faults, but NW trending topography might also be found. Detailed material and maps can be found at this site:
An indication that the NW-SE oriented mantle division line, underneath the convection rolls oriented NE-SW shaping the Reykjanes Ridge, have direct effect on the area is this map showing the changes of gravity as measured from 1975 to 1999:
Information about the measurements are found in this article: https://skemman.is/bitstream/1946/31865/1/Melissa_Thesis_report_FINAL.pdf
Geosea near Húsavík in Iceland is a new tourist attraction. The baths make use of geothermal heat in the area, originating from boreholes at the seaside.
Magic Magma 