IAVCEI 2013 Scientific Assembly - July 20 - 24, Kagoshima, Japan
Forecasting Volcanic Activity - Reading and translating the messages of nature for society

3P1_4G-O1

Room A4

Date/Time: July 23 15:00-15:15

A lengthy volcanic crisis becomes a way of life: The 14 year eruptive process of
Tungurahua Volcano, Ecuador
Patricia A. Mothes, Patricio A. Ramon, Liliana P. Troncoso, Hugo A. Yepes, Jorge E. Bustillos
Instituto Geofisico, Escuela Politecnica Nacional, Ecuador
E-mail: pmothes@igepn.edu.ec

The successful handling of the Tungurahua fourteen yr eruptive process is due to many factors. Monitoring
started by the Insituto Geofisico a decade before the 1999 reactivation and continues. The conjoined long-term
participation by IG scientists in monitoring and volcanic studies has provided an institutional memory and a threadof knowledge that is referential for making critical decisions on volcanic behavior. IG scientists, well-recognized in
the community and by officials are also key contacts for conveying volcano information and for listening to concerns
and the perspectives of local people. IG monitoring operations are conducted from the Tungurahua Volcano
Observatory, OVT, located NW of the crater and also from the main IG office in Quito. OVT has a senior scientist
and assistant who make daily diagnosis of eruptive activity, foster incoming data streams and monitoring systems,
participate in emergency committee meetings, give press interviews, and provide advice to local authorities wheneruptive activity increases. Some local farmers and community members have been selected as volunteer volcano
observers, vigias. All participated in briefings by OVT on volcano monitoring practices and also get yearly updates
at IG and SNGR-sponsored workshops. Some vigias have served for over a decade and their observations arewell-trusted. Communication by UHF radio system permits observations of vigias to be recorded and comparedwith instrumentally-derived data. Mayors and SNGR personal also interact with OVT via this radio system. Vigias
also help with installation of IG geophysical stations, their upkeep and security and at some sites they measure ash
thickness and weight. The vigias are local referents on volcano issues and they are a fundamental link between OVT
and local residents since they pass along critical information during crises and facilitate evacuations. The long-term
eruptive activity has varied between VEI 1 to 3 levels, generally allowing the continuance of agricultural and othereconomic activities. Keeping the attention of authorities and the population has been aided by on-off eruptive
cycles of 4 month intervals over the past few years. Instrumentation upgrades have been achieved in collaboration
with JICA, USAID, NOVAC, the SNGR, the Ecuadorian NSF and cooperation with French IRD scientists provided
high-quality modeling of PDCs. Incorporating data from BB seismic stations, cGPS, tiltmeters and DOAS has
refined eruptive activity prognosis. Challenges for continued monitoring includes financing the overall operations,maintaining the presence of experienced scientists at OVT and having to often instruct new officials in volcanic
hazard issues and their management. The IG maintains a web page where daily and special reports of volcanic
activity are available and links to social media can be found. The volcano is the focus of the collaborative 3 yr
STREVA project.

©IAVCEI 2013 Scientific Assembly. All rights reserved.

1228