During the powerful July 2013 eruption of Tungurahua volcano, Ecuador, we recorded exceptionally high amplitude, long‐period infrasound (1,600‐Pa peak‐to‐peak amplitude, 5.5‐s period) on sensors within 2km of the vent alongside electromagnetic signals from volcanic lightning serendipitously captured as interference. This explosion was one of Tungurahua's most powerful vulcanian eruptions since recent activity began in 1999, and its acoustic wave is among the most powerful volcanic infrasound ever recorded anywhere. We use these data to quantify erupted volume from the main explosion and to classify postexplosive degassing into distinct emission styles. Additionally, we demonstrate a highly effective method of recording lightning‐related electromagnetic signals alongside infrasound. Detailed chronologies of powerful vulcanian eruptions are rare; this study demonstrates that diverse eruptive processes can occur in such eruptions and that near‐vent infrasound and electromagnetic data can elucidate them.
This document was originally published in Geophysical Research Letters by John Wiley and Sons, Inc. on behalf of the American Geophysical Union. Copyright restrictions may apply. doi: 10.1002/2017GL076419
Anderson, J. F.; Johnson, J. B.; Steele, A. L.; Ruiz, M. C.; and Brand, B. D.. (2018). "Diverse Eruptive Activity Revealed by Acoustic and Electromagnetic Observations of the 14 July 2013 Intense Vulcanian Eruption of Tungurahua Volcano, Ecuador". Geophysical Research Letters, 45(7), 2976-2985.