The Miravalles Volcano is located 15 km to the north of Bagaces, the province of Guanacaste and belongs to the Cordillera of Guanacaste. With an elevation of 2028 meters above sea level. It is made up of at least six volcanic sources the mayority being aligned northeast and southeast. The Miravalles crater is 600 meters in diameter. At this moment in time it is presenting second class volcanic activity (smoking cones, mud pools and thermal sources) in the area named “Las Hornillas” (little ovens). It is the property of the Hotel El Guayacán. The highest point of the volcanoe is what is left of a cone, towards the southeast of this there is a small double cone that is cut because of fault towards the northeast. One of these cones is better preserved than the other. (Very erroded). The rest of the other craters are very affected by erosion located to the northeast of the other cones. The source of eruption moves from the northeast to the southeast. There are also remains of a calderic border 1 km to the southeast of the main crater. The Mogote and the Montañosa peaks in the west and those of the Espíritu Santo (979 metros), Gota de Agua (1.082 metros) La Giganta (1.490 metros) in the southeast are remains of a large paleo-caldera of 200 km2, it is refuge to some felines, deers, coyotes, tepezcuintles, peccarys and white faced monkeys among many others. There is also an extense falt area that is made up of leftover volcanic lava flow located between the borders of the caldera and the Miravalles cones.
Volcanic Activity: The history of the Miravalles-Guayabo volcanoes is as follows: Quaternary: The making of several basaltic volcanoes “volcano Guayabo”. Between 1.6 and 0.6 millions of years: Clouds of gas and ash (ignimbrites) and subsidence of the Guayabo volcano. Refill from the calderic depression. Some 400.000 years ago: Renewal of volcanic actibity and the beginning of the volcanic Macizo Cabro Muco-La Giganta. Some 10.000 years ago: Growth of the Paleo-Miravalles, migration of volcanic actibity towards the southeast and the development of the lower calderic structure. Some 8.200 years ago: Development of the present Miravalles cone. Large lava flows and avalanches that generate hot lahars (mud flows). Some 8.000 years ago: Lava trails and piroclastic deposits. In 1946 (14th of September): geothermic flows in the subsoil provoke a small phreatic explision on the southeast flank of the Miravalles.
Sistems of Volcano Vigilence: At volcano Miravalles ICE has 6 seismic stations and a accelerograph located at the Miravalles Geothermic Camp, as well as a network of 10 stations of dry inclinometry, studies of exact levels and microgravity. The OSIVAM monitor the seismic activity around this volcano (siesmic statiosn and strong movement equipment).
What to take
Insect repellent, closed shoes, towel, sandals, binoculars, camera or camcorder, hat and swimsuit.