Mouth of Hell

April 19, 2010

Nicaragua 2009--Masaya 0.07[1]

Photographer: Rob Sheridan
Summary Author: Rob Sheridan

April 2010 Earth Science Picture of the Day Viewer's Choice

The Caribbean Plate is overriding and burying the Cocos Plate along the Pacific coast of Central America. Volcanism at this subduction zone began about 15 million years ago (mya) and closed the gap between North and South America about 3 mya. The separation of the Atlantic and Pacific Oceans profoundly changed the ocean circulation and perhaps the global climate. Just offshore, the subduction zone forms the Mesoamerican trench, and just inshore, it fuels the Central American Volcanic Arc (CAVA). This is a chain of active shield and stratovolcanoes running the length of Pacific Central America. The huge Masaya Shield Volcano is part of a massive volcanic complex that lies 13 mi (21 km) south of Managua, Nicaragua. A shield volcano is formed by repeated flows of relatively low-viscosity lava. These volcanoes have long, shallow sides, unlike the peaked cones of stratovolcanoes. Masaya nearly continuously emits steam and noxious sulfur dioxide gas and has extruded vast flows of lava as recently as 1852. Small explosive events are not infrequent.

Aboriginal Mesoamericans revered Masaya. Early Spanish explorers labeled it "La Boca del Infierno" (the Mouth of Hell). Subsequent colonizers erected "La Cruz de Bobadilla" (Father Bobadilla's Cross) on the highest lip of the crater, to keep the devil from emerging. The Masaya Shield is the only active volcano in the Americas that can be accessed to its rim by tourists, and is the centerpiece of Nicaragua's amazing and beautiful Masaya National Park. Hiking to La Cruz de Bobadilla is a popular tourist activity and is where this photo was taken on December 11, 2009.