Acoustic Signals of a Meteoroid Recorded on a Large-NSeismic Network and Fiber-Optic Cables

Abstract

A common challenge in acoustic meteoroid signal analyses is to discriminate whether the observed wavefield can be better described by line-source or point-source models. This challenge typically arises from a sparse availability of observations. In this work, we present an outstanding record of ground-coupled waves from local large-N seismic and distributed acoustic sensing (DAS) observations of a meteoroid in Iceland. Our complete data set includes additional regional stations located within 300 km of the meteoroid’s trajectory. The dense large-N and DAS data allow identification of acoustic phases that are almost impossible to discriminate on sparser networks, including a weak late arrival resolved mostly only by DAS. Using this data set with a new Bayesian inversion model, we estimate the trajectory parameters of one fragment from the meteoroid. With these results we investigate its orbit in the solar system and propose a classification of the Icelandic event as a slow meteoroid of asteroidal origin with an energy on the order of 4–40 GJ, a probable size on the order of centimeters, and an orbit range consistent with the main asteroid belt.

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

“…Acoustic and coupled seismic energy from falling meteoroids can be recorded by infrasound and seismic sensors (Brown et al, 2003;D'Auria et al, 2006;Edwards et al, 2008;Ishihara et al, 2003;Langston, 2004;Pujol et al, 2005Pujol et al, , 2006Stich et al, 2022;Tatum, 1999;Vera Rodriguez et al, 2022;Yamada, 2021). Infrasound sensors typically record characteristic N-waves (Kanamori et al, 1991), whereas velocity records are W-shaped (D'Auria et al, 2006;Langston, 2004).…”

“…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). Other factors that complicate the modelling of seismoacoustic observations include multipathing, ground-coupled precursory signals, and site effects generating variable signal durations (Stich, 2022).…”

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

“…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). 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).…”

“…Acoustic and coupled seismic energy from falling meteoroids can be recorded by infrasound and seismic sensors (Brown et al., 2003; D’Auria et al., 2006; Edwards et al., 2008; Ishihara et al., 2003; Langston, 2004; Pujol et al., 2005, 2006; Stich et al., 2022; Tatum, 1999; Vera Rodriguez et al., 2022; Yamada, 2021). Infrasound sensors typically record characteristic N ‐waves (Kanamori et al., 1991), whereas velocity records are W ‐shaped (D’Auria et al., 2006; Langston, 2004).…”

“…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).…”