ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2023-11-23
    Description: The explosion at the Ingolstadt oil refinery was widely recorded at seismic and infrasound stations deployed throughout Central Europe, to distances of several hundred to a thousand kilometres. This study focuses on the wealth of data recorded at infrasound stations in Central and Eastern Europe, while from the many detecting seismic stations within 400 km range, only seismic and seismo-acoustic arrivals at the close-in Gräfenberg array are considered here. Most of the infrasound stations are acoustic arrays enabling us to apply array processing techniques to determine relevant wave field parameters, such as backazimuth and slowness (resp. trace velocity). These parameters not only confirm the source direction, but also put constraints on the observed arrivals’ propagation modes. Wave field parameters suggest that we observe tropospheric arrivals to about 150 km and stratospheric and/or thermospheric returns for longer distances. 1D, 2D and 3D ray tracing predict tropospheric arrivals to westerly directions up to distances of 100 km, beyond which only thermospheric returns are obtained azimuth-independent beyond 250–300 km. Stratospheric returns do not follow from any of the increasingly complex ray tracing models. Parabolic equation propagation modeling however suggests that in a number of cases stratospheric ducting may be possible. However, neither the tropospheric seismo-acoustic arrivals at the Gräfenberg array nor the various arrivals at IMS station IS26 could be modeled. Therefore, the Ingolstadt explosion along with the observed infrasonic phases provide an excellent test bed to investigate our ability in realistically forecasting atmospheric wave propagation with existing algorithms and available atmospheric models.
    Keywords: ddc:551.5 ; Infrasound ; explosion ; atmospheric models ; propagation modeling ; stratospheric ducting
    Language: English
    Type: doc-type:article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2023-11-27
    Description: The Baumgarten explosion occurred on 12 December 2017 at a gas storage site about 30 km east of Vienna, Austria. Acoustic arrivals from this accidental surface explosion were detected at dozens of stations of the AlpArray seismic network to distances up to 150 km, mainly in easterly directions. Thus it was expected that the Hungarian infrasound array PSZI located about 230 km to the east-southeast of Baumgarten would detect this acoustic wave as well. Standard progressive multichannel correlation processing and frequency-wavenumber analysis identified a signal emerging at 7:57:55 UTC from an azimuth of 296°–300° and with trace-velocity 〉 400 m/s. The extraordinarily high trace-velocity and excessive backazimuth residual, relative to the explosion site direction of 282°, however cast strong doubts on the arrival’s connection to the Baumgarten event. Accounting for the effect of non-planar geometry of the infrasound array results in a reduction of the azimuth residual by half. Additionally, 2D and 3D raytracing methods are used including the European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric model to further explain the remaining azimuth residual as well as to elucidate the large trace velocity estimates. The prevailing stratospheric winds in excess of 150 m/s are identified as the underlying cause. Including both factors the initial azimuth residual of up to 18° decreases to ~ 4°, allowing to associate the infrasound signal at PSZI with the Baumgarten event. Finally, the data from a seismic station at 30 km range is re-investigated for magnitude estimation. The local magnitude of ML 〈 1.0 explains well the scarcity of seismic observations within 50 km range, where three or four stations show signals, mainly consisting of Rg-type surface waves, but no body waves.
    Description: https://www.geofon.gfz-potsdam.de/doi/network/HN
    Description: https://doi.org/10.14470/UA114590
    Description: https://www.geofon.gfz-potsdam.de/doi/network/SK
    Description: https://www.ecmwf.int/
    Description: https://www.github.com/LANL-Seismoacoustics/GeoAc
    Keywords: ddc:551 ; Infrasound ; Baumgarten explosion ; array data processing ; backazimuth residual ; atmospheric sound propagation ; detection threshold
    Language: English
    Type: doc-type:article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2021-07-21
    Description: Infrasound array processing is applied to monitor and characterize atmospheric explosions in the context of the Comprehensive Nuclear‐Test‐Ban Treaty. Anyhow, for many infrasound sources the exact location and time are initially unknown and sometimes difficult to precisely estimate afterward. In contrast, rocket launches are well‐defined ground‐truth events generating strong infrasonic signatures. During the last decade, the number of rocket launches for sending satellites into Earth’s orbit and for reaching space strongly increased. We collected ground‐truth information for 1001 rocket launches from 27 global spaceports between 2009 and mid‐2020 and were able to identify infrasound signatures from up to 73% of the launches on the International Monitoring System of infrasound stations. We use these unique data to estimate the global detectability of such events, to characterize rocket infrasound, to derive an amplitude‐energy relation, and to provide the results for further use as a ground‐truth reference in geophysical and atmospheric research.
    Description: Plain Language Summary: The launching of rockets from spaceports like Cape Canaveral, USA or Baikonur, Kazakhstan produces extremely loud sounds that can be heard at large distances. Similar to the basses of a large concert there are deep sounds that travel even farther, up to thousands of kilometers, through the air. This sound below what humans can hear, so called infrasound, can be collected by extremely sensitive instruments, similar to microphones for recording music. Within our study we were able to identify the sound of 733 out of 1001 rocket launches, performed within more than a decade of spaceflights, to bring satellites, astronauts, or cargo into space. We look at the tone of these starts to find out which types of rockets are best detected at which infrasound stations; and why. We furthermore make our findings available for scientists that want to learn more about the rockets that produce the sound, the air that transports it, and the instruments that record it.
    Description: Key Points: We analyze 1001 rocket launches since 2009 using International Monitoring System infrasound arrays. We estimate the global detectability, individual signal characteristics, and an amplitude‐energy relation of rocket infrasound. We provide a ground‐truth data set of signal parameters for 7637 infrasound events from 733 launches.
    Keywords: 550 ; CTBT ; IMS ; infrasound ; rocket launch
    Type: article
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...