66°N symmetry – Iceland – Greenland – Norway

As tectonic drift is due to the flow of magma, the pattern of magma flow affects the arrangement of tectonic plates. A manifestation of such arrangement is found along the latitude of 66°N. There are exactly 30° in between the west coast of Iceland and the west coast of Greenland along that latitude. Also, from the Icelandic coast to the abyss of Norway there are also 30° along 66°N.

Greenland-Iceland-Norwegian Basin at 66N

Coincidence? Sorry, no way! Not to be understood? Not acceptable, because we are obliged to understand things like that, screaming and kicking!

Looking a bit more carefully, you will see that there are 6° along 66°N from the Norwegian abyss to the Norwegian coast. Also, from the west coast point of Iceland, there are exactly 6° to the central magma division line of lower mantle. That logically means that from the central line to the coast of Norway along 66°N there ara exactly 30°. That means the coast of Norway at that point is directly above the main division line of large lower mantle cells (as each of them spans 30° from east to west).

One out of endless mysteries of magic magma!



The Mid-Atlantic Ridge zik zak

The Mid-Atlantic Ridge sways rather regularly throughout the N-Atlantic sea bottom. The two large convection rolls which must be found at each side of it, can not make jumps or sway irregularly, becuse it is composed of flowing mantle. It must therefore be shaped according to the Earth’s radius and in coherence with the rotation of the Earth.

Mid-Atlantic Ridge - the zikzak

The crossing between mantle division line of the large cells and the Mid-Atlantic Ridge is found at 32°N, which is where the mantle rolls division line is exactly oriented NS.

The magma flow therefore tends to find its way west of the central line in southern latitudes, but east of it north of 32°N. Then it follows the middle line closely along the Reykjanes Ridge, following the next upwelling line east of the main line.

Again, at equator, the two lines merge into one.



Following the grid, understanding the geology of Iceland – and the World

The map shows it all 🙂 The volcanic sites in Iceland are arranged in a systematic way. First, the Reykjanes Ridge is found along a calculated line extending through the middle of the Atlantic Ocean, with a starting point at equator exactly 30° awy from the coast of S-America on one side and 30° from the coast of Africa on the other side. Then the grid shows how the tectonic plates meet in Iceland. One aspect is the NS-axis from Öræfajökull to Öxarfjörður. Then the Tjörnes Zone in the North shows very clearly the function of the polygon system over Iceland.

Following the grid

It can not be more clearly manifested. Explaining in this way the geology of Iceland makes it easier for comprehend the volcanism, geothermal activity and the geological history of Iceland. With the mechanism in mind, and when everything can be calculated mathematically, it becomes easier to trace changes back in time.



The upwelling and downwelling lines of Iceland

Downwelling means a tendency to converge, and upwelling means divergence. The small scale convection rolls intervene with the main trend following the large convection cells of lower mantle. That main line lies through the middle of the country from SW to NE. The two southern volcanic zones, called WVZ and EVZ, are found within the same settings, namely with upwelling to the west and downwelling at the eastern side. The reason is conflict between the tectonic drift to the NW and the opposite trend resulting from the upwelling and downwelling lines.

Upwelling and downwelling

The MIVZ in central Iceland actually also has this setup, but to the NE and SW. The shift of tightness of the polygons at 65°N results in almost continuous volcanic areas from Snæfellsjökull to Snæfell. Then there is the NS-axis from Öræfajökull to Axarfjörður, besides the less known NS axis from Eyjafjallajökull through Hekla to Drangey.


The Katla Volcanic System

How to explain the existence of the EVZ and Katla volcanic system? We can analyze it by looking at the convection cell system, its lines and polygons. Katla takes over two polygons as shown here:

Katla Volcanic System

The four lines are all downwelling. The caldera is found in the east corner of the southern polygon. When magma finds its way out of the caldera, it flows along the fissures exactly from one side to another of the northern polygon. The tension is created by the conflict between large scale tectonic drift, pulling from NE to NW, and the small scale (1.5° wide) pulling of the uppermost convection roll under the EVZ from NW to SE.

To see this more clearly, zoom in a bit:

Katla - hyrningar - þysjað

The violet color shows Katla Volcanic System, both caldera and the fissure swarm extending to the NE. The other fissure swarm, extending from NE to SW, is the Grímsvötn system, where the caldera is also found adjacent to a corner of the relevant polygon.