'TUNGURAHUA VOLCANO - 26 April 2011 and 2006 'Tungurahua is an active strato-volcano located in the 'Cordillera Oriental of Ecuador. Volcanic activity restarted in 1999, and is ongoing as of 2011, with major eruptions. Ecuador's Tungurahua volcano hurled truck-sized pyroclastic boulders more than a mile Friday in a powerful eruption that prompted at least 300 people to flee their homes. The smallest blocks are that size of an automobile while the biggest reach the size of a truck, which cause impact craters up to 10 meters (33 feet) wide as they hit the flanks. The Tungurahua volcano spews ash and steam during the eruption.
Causes of Eruption: Rapid decompression of magma in a shock tube has been considered to be an important mechanism for explosive eruptions triggered by ruptures at the magma surface. However, our study suggests that explosive eruptions are triggered by pressure disturbances in magma at depth.
Impacts: 'Several pyroclastic flows were generated that killed seven people, and destroyed a number of hamlets and roads on the eastern and northwestern slopes of the volcano. The seven people who died were a family of five and two scientists. There are also damages to crops, pastures and small effects to the health of people. 'Ecuador’s active Tungurahua volcano had its biggest eruption yet, leading to the displacement of thousands of children and families who now remain homeless and in need of humanitarian assistance. The eruption affected six provinces: Tungurahua, Chimborazo, Bolivar, Los Rios, Guayas and Manabi. A high number of explosions were registered, accompanied by volcanic tremors and gas and ash emissions that continued for 36 hours. Pyroclastic flows and other volcanic material destroyed roads, houses, infrastructure, crops and pastureland. Since the time to plant crops is approaching, there is concern that farmers will have a poor harvest next year. Their cattle are also experiencing serious health problems, some leading to death, from grazing in ash-covered pastures.
Prediction: 'VDAP’s long-term relationship with and technical assistance to Ecuador’s Instituto Geofísico helped successfully forecast the eruption at Tungurahua volcano in August 2006. Again, careful monitoring and interpretation of the volcano’s behavior and characteristics permitted the timely evacuation of 19,000 residents from the danger zone. VDAP also replaced the seismic- monitoring equipment destroyed in the eruption. VDAP’s efforts encompass a range of mechanisms that draw from OFDA’s technical assistance capacity and expertise.
'Mitigation: 'local authority with scientists cooperation must improve again the quality of information for the population concerning the risks and discouraging individuals or families who will run these risks from returning to their homes and activities in the unsafe area. Hazards mitigation during an eruption depends on a continuous monitoring, as well as a reliable hazard map. The latter is the starting point for develops risk maps, territorial planning and emergencies management. In fact, the early warning provided by the IG-EPN to the local authorities allowed the evacuation of thousands of people living in the high-hazard zone. As a result, human loss was limited to 6 fatalities. In this abstract, we will describe the 2006 eruptions, and the importance of the volcano hazard maps and their diffusion for hazard assessment and emergency planning. The good practices at the community level for risk management of natural and man-made disasters that affect the food security of communities vulnerable to the Tungurahua. This systematization is an analytical reconstruction process, both from an institutional perspective, as well as a socila perspective on the capacities of members of a society or community, in this case farmers, to face shocks and hazards, preventing and minimizing the damage, mitigating the effects of adverse events to ensure the provision of food and agricultural production. Ecuadoran officials have called for evacuations of the slopes of Tungurahua after the volcano increased its ash emissions and explosions, including the production of some pyroclastic flows.
'Response: Fieldwork involved interviewing government officials, selecting focus groups and conducting surveys of evacuees in four locations. 'Some 19,000 people were evacuated to shelters set up mainly in schools and sports arenas. An estimated 4,750 people – including about 2,000 children – are living in these shelters. Many others have found refuge in the homes of relatives or friends.
It also prompted the National Oceanic and Atmospheric Administration's (NOAA) Washington Volcanic Ash Advisory Center (VAAC) in Maryland to issue a warning to any airplanes flying near or into Quito, Ecuador. Officials say that most people were safely evacuated Wednesday from many of the villages on the slopes, just hours before Tungurahua erupted. Some local residents, however, refused to leave.
Done By: Chua Ya Zhen, Bernice Ho, Keith Tan