Acoustic signals of a meteoroid recorded on a large-N seismic network and fiber-optic cables
Acoustic signals of a meteoroid recorded on a large-N seismic network and fiber-optic cables
Seismological Research Letters (November 2022) 94 (2A): 731-745
- ablation
- acoustical waves
- arrays
- cryptoexplosion features
- Europe
- fireballs
- geophones
- Iceland
- impacts
- meteoroids
- NORSAR
- orbits
- seismic networks
- seismic sources
- shatter cones
- trajectories
- Western Europe
- southwestern Iceland
- fiber optics
- infrasonic waves
- atmospheric entry
- distributed acoustical sensing
- moving source models
- COSEISMIQ
- large-N seismic networks
- Raspberry Shakes
- DEEPEN
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.