Mechanisms of Earthquakes in Vrancea

Abstract

The Vrancea seismic region is defined as an earthquake nest, meaning a particular kind of intermediate-depth earthquake concentration or clustering. First, an earthquake nest implies a volume of intense activity that is isolated from nearby activity. Second, this activity is persistent over time (at least for decades). From this point of view, nests are distinct from aftershock sequences or earthquake swarms. The definition of what represents an earthquake nest is somewhat arbitrary, and there are many regions in the world where clustering of seismic activity can be categorized as earthquake nests. Nevertheless, earthquake nests are associated to three most famous and intensively studied areas, Bucaramanga (Colombia), Hindu Kush (Afghanistan), and Vrancea (Romania).