IPATEC   26054
INSTITUTO ANDINO PATAGONICO DE TECNOLOGIAS BIOLOGICAS Y GEOAMBIENTALES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Impacts after the 2015 Calbuco eruption in Argentina and their relation to tephra deposit characteristics and climatic variables
Autor/es:
VILLAROSA, GUSTAVO; BEIGT, DÉBORA; HORWELL, CLAIRE; ARRETCHE, MARCOS; DELMÉNICO, AGUSTÍN; TOYOS, GUILLERMO; NAJORKA, JENS; STEWART, CAROL; OUTES, VALERIA; COTTET, JULIETA; DAMBY, DAVID; WILSON, THOMAS
Lugar:
Puerto Varas
Reunión:
Congreso; Cities on volcanoes COV 9: Understanding volcanoes and society: the key for risk mitigation; 2016
Institución organizadora:
SERNAGEOMIN
Resumen:
The April 2015 Calbuco eruption produced an ash cloud thatdrifted N-NE reaching the Argentinean territory in a few hours. Due toparticular atmospheric conditions, the plumes from the first and seconderuptive pulses persisted over Neuquén province for several hours. About140.000 km2 were covered in Argentina with up to 24 mm thick tephra composed ofbimodal fine ash. Tephra distribution and climatic variables (high W-Eprecipitation gradient, dominant strong westerly winds) favored frequent andmassive ash resuspension events in central Neuquén, comparable to the situationof central Rio Negro province after Cordón Caulle (CC) 2011 eruption. XRDanalyses disagreed with the significant presence of cristobalite indicated inearly reports.  The impacts were investigatedin three towns along the axis of the deposit and related to tephracharacteristics and climatic variables. Damage to infrastructure, increase inturbidity and changes in pH were recorded in water supplies, as well asproblems in wastewater treatment systems caused by wearing of equipment andclogged filters. Adaptation of the insulators introduced after the 2011 CCeruption prevented significant impacts from adhered ash on electricitytransmission lines. Economic activities in touristic towns were significantlyaffected, with a sharp decline of ~50% in hotel occupancy observed during May2015. Many cases of bronchitis, bronchiolitis and asthma were reported,particularly in Junín de los Andes (JLA) where severe conditions were caused bywind resuspension of ash. The 2011 CC eruption led to a change in volcanic riskconsciousness in the most affected localities such as Villa La Angostura (VLA).Though it is still necessary to enhance the emergency preparation and reducethe exposure of critical infrastructure to ashfall events in the region,preparedness and response to the 2015 Calbuco crisis proved to be moreeffective in VLA with respect to JLA and other previously unaffected towns