Petra, I don't really understand your question-matter in what way? I did not go and check the exact location, depth, and slip sense of these quakes, except Brazil. But, all 4 of them are in areas of subduction zones-Kamchatka is very volcanic also. Most subduction zones have associated volcanic arcs. But, earthquakes within the subducting slabs (the deep Brazil earthquake) or between the slab and the upper plate, would not directly be volcanic quakes. Volcanic quakes would be very close to/right under the volcanos and in some way associated with the magma chamber/conduits/dikes. I don't think any of these large quakes were of this type, but I did not check except for Brazil.