where are the poles of rotation of the tectonic plates located?
Up to now, we constrained the (relative) plate movements mostly with seismic slip measurments. 

Since 10-20 years, with the diffusion of GPS measurments, it has been possible to have a more granular distribution of movements and a more precise estimation of the rotation pole for a given plate.

Roughly speaking, then, you should look for the work of authors like these:
https://meetingorganizer.copernicus.org/EGU2017/EGU2017-14816-1.pdf (just a random "scientific" google result for the search)

The end product (an accurate determination of rotation poles) should help in estabilishing the seismic hazard, by observing gaps and differential displacements, possibly representing loading of the fault, in a very primitive Reid (1910) way of thinking:


https://earthquake.usgs.gov/earthquakes/events/1906calif/18april/images/ElasticRebound.gif

I have no right on the image, it comes from the USGS site.