Observation of tsunami-generated ionospheric signatures over Hawaii caused by the 16 September 2015 Illapel earthquake

Tsunamis generate internal gravity waves (IGWs) that propagate vertically into the atmosphere and can create detectable signatures in the ionosphere. These signatures have consistently been observed in the presence of a tsunami for over a decade in the total electron content and for over 5 years in the 630.0 nm airglow. Here we show perturbations appearing in filtered GPS-derived total electron content (TEC) and 630.0 nm airglow above Hawaii during the passing of the tsunami induced by the 16 September 2015 earthquake in Illapel, Chile. We report measurements of IGW parameters from both observation methodologies using a combination of prior methods and a newly developed method that uses a Gabor filter bank. A previously developed geometric model that takes into account the assumed posture of tsunami-induced IGWs in the geomagnetic field and the observation geometry is shown to predict fairly well the expected location of the observation in the sky. Results of the Gabor filtering technique are also compared to previously published results for the 11 March 2011 Tohoku event. An overall comparison between all of the tsunami-induced signatures that have appeared in both the 630.0 nm airglow and TEC above Hawaii to date is provided.