Seismic Observation and Location of a Meteor Burst From a Dense Station Deployment in Southern Spain

Abstract

The evening of 11 December 2016, near 22:25 local time (21:25 UTC), a meteor event with absolute magnitude m = −17 was observed from most of Spain. The event was recorded by meteor observing stations operating at different astronomical observatories in southern Spain (Madiedo, 2017). According to reports in news and social media, the meteor event produced a bright, white light in the night sky for several seconds, and was widely heard and felt. Eyewitness accounts mention an audible boom, ground vibration or tremor, and windows rattling at several places in the province of Granada. Many people have mistaken these vibrations for a weak earthquake. The testimonies point to the arrival of pressure waves on the ground. Such sound and infrasound signals are originated by the interaction between the atmosphere and the meteoroid, and might be related to the shock wave from the meteoroid passage at hypersonic speed, or to an explosive fragmentation event induced by frictional heating of the meteoroid in the atmosphere (e.g.,

Exclusive Seismoacoustic Detection and Characterization of an Unseen and Unheard Fireball Over the North Atlantic

“…We only found obvious seismic signals from São Miguel Island, which aligns with previous observations of similar events within a limited area of ∼100 km 2 (D’Auria et al., 2006; Stich et al., 2022). However, we found weak signals with low signal‐to‐noise ratios at four stations on Terceira Island, ∼150 km to the NW (Figure 1a), with arrival times consistent with the moveout velocity observed elsewhere (Figure 3).…”

“…Monochromatic seismic waveforms (e.g., at CP.PVER) indicate air‐coupled Rayleigh waves generated in a near‐surface layer with a velocity slower than that of the air above (Albert et al., 2013; Anthony et al., 2022; Edwards et al., 2007). In contrast, weak precursory signals detected at PM.BART and PM.PGRON may represent coupled Rayleigh waves that form in a near‐surface layer with a velocity faster than that of air (D’Auria et al., 2006; Edwards et al., 2008; Langston, 2004; Stich et al., 2022).…”

“…However, distinguishing point sources from moving sources is challenging, particularly with limited observations (Vera Rodriguez et al., 2022). Other factors that complicate the modeling of seismoacoustic observations include multipathing, ground‐coupled precursory signals, and site effects generating variable signal durations (Stich et al., 2022).…”

“…Studies on meteoroids primarily rely on initial visual and/or audible human observations (Brown, ReVelle, et al., 2002; Brown et al., 2003, 2011; D’Auria et al., 2006; Hughes et al., 2022; Ishihara et al., 2003; Kumar et al., 2017; Langston, 2004; Llorca et al., 2005; Pujol et al., 2005; Stich et al., 2022; Vera Rodriguez et al., 2022; Walker et al., 2010; Yamada, 2021; Yamada & Mori, 2012), leading to an observational bias toward populated areas, such as on the continents. Observations over oceans and islands are notably scarce, particularly without all‐sky cameras (Silber & Brown, 2014).…”

“…One assumes straight rays and a constant velocity of sound through the atmosphere (Ishihara et al., 2003; Kumar et al., 2017; Langston, 2004; Pujol et al., 2006; Yamada, 2021; Yamada & Mori, 2012). The other involves ray‐tracing in realistic atmospheric models while accounting for wind effects (Walker et al., 2010) to reconstruct the acoustic raypath in the atmosphere (Brown et al., 2003; Hedlin et al., 2010; Stich et al., 2022). However, distinguishing point sources from moving sources is challenging, particularly with limited observations (Vera Rodriguez et al., 2022).…”