Partitioning of strike‐slip and convergent motion between Eurasia and Arabia in eastern Turkey and the Caucasus

The plate motion model NUVEL‐1 (De Mets et al., 1990) predicts a strongly oblique component to the convergence between Arabia and Eurasia at the longitude of the Caucasus. Earthquake focal mechanisms suggest that this oblique convergence is partitioned into pure right‐lateral strike‐slip motion in eastern Turkey and pure shortening by thrusting in the Greater Caucasus. Such partitioning offers an explanation for the apparent eastward continuation of the right‐lateral faulting of the North Anatolian fault from Turkey into Iran. From a summation of seismic moment tensors between 1911 and 1991 it appears that most of the right‐lateral strike‐slip motion in eastern Turkey is accommodated by faulting in large earthquakes, while most of the shortening in the Caucasus appears to occur aseismically.