Recent volcano monitoring in Costa Rica

The Costa Rican volacno Rincon de la Vieja is loosely but mysteriously translated as the "Old Lady's Corner." It consists of six volcanic centers that form a remote elongated ridge standing some 1300m above the surrounding terraine. Geologically speaking, the Guanacaste province of northern Costa Rica consists of a series of composite volcanic cones built on a shield of ignimbrites (welded and unwelded ash flows) of Pliocene-Pleistocene age (up to 2 million years old), that themselves lie on basement crust of Cretaceious-Tertiary age (up to 90 million years old). the active volcanoes are aligned on a northwest-southeast axis parallel to the Middle American oceanic trench in the Pacific Ocean that is the site of subduction of hte Cocos oceanic plate underneath Central America.