We investigate 20 years of seismicity at Húsavík–Flatey Fault (HFF) and Eyjafjarðaráll Rift (ER) a ridge-transform segment in Northern Iceland. We find that tectonic earthquake swarms (TES) have efficiently tiled these faults. The spatial organization of TES show complementarity with later swarms do not occur in segments previously interested by earlier swarm activity. The spatial complementary and low stress drop suggests aseismic strain release associated with TES. The analysis of the seismicity in terms of foreshocks and aftershocks productivity is consistent with aseismic forcing behind the TES. Low effective normal stress maybe associated with abundance of fluids may favor seismic/aseismic strain release at this ridge-transform segment.

| Earth and Planetary Science Letters | DOI: http://doi.org/10.1016/j.epsl.2017.10.052 |