The Laptev Sea and adjacent areas represent a unique region where continental rifting is occurring on a direct extension of a mid- oceanic ridge system and where the pole of rotation between two plates lies approximately on the plate boundary separating them. Due to the inaccessibility of this region and the moderate level of seismicity, study of its present day tectonics by direct means is difficult. Therefore, it is one of the least understood regions of the world. Advances in seismological analysis techniques allow the study of earthquakes of smaller magnitude and in larger numbers than was previously possible. This investigation will study focal mechanisms and depths of earthquakes along the North America - Eurasia plate boundary as it changes first from an oceanic to a continental rift, and then into a zone of thrusting and strike-slop motion. Seismological data will be supplemented by Landsat imagery and Soviet geologic data to aid in interpretations. These studies will contribute to understanding the tectonic evolution of the Arctic Ocean, continental rifts, and the evolution of intracontinental plate boundaries.
