Wind directions of volcanic ash-charged clouds in Ecuador–implications for the public and flight safety

Abstract

Ecuador has about 20 active continental volcanoes, with a volcanic explosivity index (VEI) between 2 and 7. In the last 17 years, five of these volcanoes (Sangay, Guagua Pichincha, El Reventador, Cotopaxi and Tungurahua) have manifested their activity with thousands of eruptions, some of them even capable of compromising public health, closing airports and affect main national and international air routes. Therefore, these eruptions have been evaluated taking into account wind directions of the ash-charged clouds using the archives of the NOAA’s Ecuador Satellite Imagery of the Satellite Services Division of the National Environmental Satellite, Data, and Information Service. The main wind direction of these ash clouds demonstrate a clear uniform E–W direction for the months between April and September, while other months vary slightly from this main direction. As early warning systems for volcanic activity prior and even after eruptions have frequently failed for the last 17 years in Ecuador, the evaluated statistics of wind directions of the ash-charged clouds will improve the hazard evaluation and assessment. These statistics with a complementary interpretation of remote sensing will most likely be an enhanced tool in volcanic hazard assessment in Ecuador than it has been so far.