This (almost) daily post intends to follow up the activity changes of volcanoes all over the world.
This post is written by geologist Richard Wilson who specializes in Volcano seismicity and Armand Vervaeck. Please feel free to tell us about new or changed activity if we haven’t written about it. -
September 8, 2012 volcano activity
Nicaragua’s largest volcano erupted three times this morning, belching gas and ash 1,500 meters into the sky and forcing the evacuation of thousands of families in the rural northwestern department of Chinandega, according to government media sources. No damages or injuries have been reported. San Cristobal’s eruption is being monitored by the government officials and could result in the evacuation of 20,000 people, according to first lady and government spokeswoman Rosario Murillo.
Update : Nearly 3000 people living in La Bolsa, Versalles, El Pando, Pellisco and Apazate are relocated. President Ortega is carefully following up the situation and says that he may order a second eveacuation for approx. 20000 people. 400 people from the Civil Defense have been asked to be ready in case the evacuation will be ordered.
Costa Rica volcanoes and the massive earthquake
After the Mw 7.6 earthquake on September 5th., 2012 (08:42 local, 14:42 GMT) on the Nicoya Peninsula, Costa Rica, concern raised about the possibility of depressurization in the volcanic range and consequently changes in the volcanic activity. Preliminary results do not show any affectation on the volcanic activity. The seism that took place ~35km depth, 20 km south of Sámara (9.696N, -85.49W) on the Nicoya Peninsula (NW of the country) had minor effects in the country considering the magnitude, and aftershocks (more than a 1,000 on September 7th) are occurring around the epicentral area and beyond the volcanic range.
After field investigation and collection of information, the scientists of the volcano observatory (OVSICORI-UNA) are reporting that only small gravitational collapsed occurred without modifying the volcanic activity of the five monitored volcanoes.
The most affected volcano, Arenal, suffered moderate rock avalanches up to the middle of the flank, mainly from the unstable blocks on the north rim of the crater. Minor rockfalls were reported from Irazú´s main crater walls. Rincón de la Vieja, Poás and Turrialba do not show significant changes related to this seismic event.
Video eruption San Cristobal volcano