Author: Steingrimur Thorbjarnarson

In Iceland divergent boundaries between plates can be watched directly. Plates also meet in Siberia, but in much more obscure way. Map showing the exact location is hard to find. There should be similar logic everywhere for boundaries between tectonic plates, so let us check Siberia:

The so called MORVEL model shows most plates location, so please compare it to what is shown here. The exact comparison can then be made in a similar way as for Iceland where every detail of how the plates are deviding from each other can be traced accurately with the mantle convection cell model.

Each continent has a position in dynamic puzzle of Earth. Here is Australia:

At the latitudes where Australia and Antarctica split apart a 100 million years ago, close to 60°S, Australia would span 60° from east to west. Drifting northwards with the role of a puzzle it maintains the shape of the time when it split apart from Antarctica. Scientists can then easily “play back” the continental drift to the exact position where the division process took place. Looking forward to it.

Considering that Iceland has symmetrical drift vectors, pointing NE and NW respectively, how did the Reykjanes Ridge get mirrored magnetic anomalies compared to its axis aligned NE-SW? We can have a look into it:

The rotation of N-American and Eurasian plates (along with Africa) is rather symmetrical and in coherence with the directions found in eastern and western parts of Iceland. If these vectors were prolonged along the Reykjanes Ridge, this would make no sense. The puzzle is dynamic, and whereas the Charlie Gibbs Fracture Zone can explain the discrepancy, another drawing on a map is added:

If the Reykjanes Ridge remains stationary over the relevant division line between upwelling convection rolls, when the sea bottom south of Charlie Gibbs is shifted eastwardards compared to the convection cell system, then the Ridge can be regular. When it comes to Iceland, a similar shift is found in Southern Iceland, and in Northern Iceland the division line is directed NS.

If this mechanism is active, it should also be measurable. In the South Atlantic, the ridge is mainly NS oriented.

Before we thought about the plates of N-America and Europe as splitting apart. Now we know more, namely that they rotate in opposite directions. Finding it out is not enough, though. We have to learn it.

Please compare this with actual data, for instance of Landmælingar Íslands and NASA.

Also note the two vectors from Iceland. The vectors found in NW and NE of the country are symmetric around NS-axis (same deviation from North). It shows the role of the main mantle division line drawn on the basic map. These vectors are parallel to the rotation found farther to the south on the two continents.

The speed of the tectonic drift in Iceland is close to 2.5 cm a year, oriented towards NE and NW. It is faster than previously thought, when only the division rate of a little less than 1 cm a year for each plate was measured.

A NASA website shows the accurate data. Generalizing the vectors showing the drift, we get a picture like this (please compare with the proper measurements):

This is quite in harmony with the opposite rotation of North America. The radius of rotation is considerably larger, as the Eurasian Continent spans 150° along the 51st parallel, but North America spans over only 60° at the same latitude.

This provides a base to analyze the tectonic drift further. Scientists can pinpoint the rotation points etc.