The Array Analyzing of The High Quality Glacial Seismic Events Active in Greenland Using Long-Period Surface (Rayleigh) Wave Detection by the German Regional Seismic Network

Abstract

This study reports on four high quality glacial events in Greenland, M 4.9, 2007-07-04; M 4.8, 2007-07-09; M 4.7, 2007-07-09; M 4.7, 2007-07-20 detected using the long-period surface waves (Rayleigh wave) recorded at the stations of the German Regional Seismic Network (GRSN) array (German-GR and Geofon-GE programs). The waveform patterns of the detected slow events for Greenland updated through 2008 were monitored to analyze this new class of low-frequency earthquakes in the context of the array processing technique and array parameters using the software Seismic Handler Motif (SHM). The array geometry of GRSN was defined by seven stations and processed to associate seismic phase arrivals to define glacial events. Two stations of GRSN were assigned the role of reference sites. The long-period surface wave characteristics of the event signals with magnitudes M 4.9, M 4.8, M 4.7, and M 4.7 were detected using filtering, beamforming, and location-relocation steps; then, the results were updated using SHM. The event data were filtered with a Butterworth band pass filter of 35s-70s with a common amplification. Using the array-beamforming technique, the beam traces were computed to calculate the beam-slowness (the apparent velocity) and the beam-azimuth of incoming wavefronts for particular time intervals to further analyze the observed glacial events. Then, the detected event signals were relocated and used to estimate array parameters; beam-slowness and beam-azimuth. Finally, in this study, the array processing technique was used with array parameters computed from the SHM to detect and analyze the slow glacial events using the array installation data from GRSN.

Keywords:

Seismology; Glacial seismicity; Surface waves, Array network

DOI: 10.17350/HJSE19030000091

Full Text: page_white_acrobat.png

Downloads

Download data is not yet available.

References

1. Nettles M, Ekström G. Glacial earthquakes in Greenland and Antarctica. Annual Review of Earth and Planetary Sciences 38 (2010) 467-491. doi:10.1146/annurev-earth-040809-152414.

2. Ekström G, Nettles M, Abers GA. Glacial earthquakes. Science 302 (2003) 622–624.

3. Ekström G, Nettles M, Tsai, VC. Seasonality and increasing frequency of Greenland glacial earthquakes. Science 311 (2006) 1756 –1758.

4. Tsai VC, Ekström G. Analysis of glacial earthquakes. Journal of Geophysical Research 112 (2007) F03S22.

5. Ekström G. Global detection and location of seismic sources by using surface waves. Bulletin of the Seismological Society of America 96 (2006) 1201–1212.

6. Kawakatsu H. Centroid single force inversion of seismic waves generated by landslides. Journal of Geophysical Research 94 (1989) 12363–12374.

7. Stammler K. SeismicHandler - Programmable multichannel data handler for interactive and automatic processing of seismological analysis. Computers & Geosciences 19 (1992) 135–140.

8. Korn M. (Ed.). Ten years of German Regional Seismic Network (GRSN): Report 25 of the Senate Commission for Geosciences. Deutsche Forschungsgemeinschaft, Wiley-VCH Verlag, Weinheim, 2002.

9. Trnkoczy A, Havskov J, Ottemöller L. Seismic networks, in: Bormann P. (Ed.). New Manual of Seismological Observatory Practice (NMSOP). Deutsches GeoForschungsZentrum, Potsdam, pp. 1-60, 2009.

10. Schweitzer J, Fyen J, Mykkeltveit S, Kvaerna T. Seismic arrays, in: Bormann P. (Ed.). New Manual of Seismological Observatory Practice (NMSOP). Deutsches GeoForschungsZentrum, Potsdam, pp. 1-52, 2009. doi:10.2312/GFZ.NMSOP_r1_ch9.

11. Tur, H, Hoskan, N., Aktaş, G., 2015. Tectonic evolution of the northeastern shelf of the Marmara Sea (Turkey): interpretation of seismic and bathymetric data. Mar. Geophys. Res. v. 36: 1-34. Doi: 10.1007/s11001-014-9230-z.

12. Gökaşan, E., Tur, H., Ecevitoğlu, B., Görüm, T., Türker, A., Tok, B., Çağlak, F., Birkan, H., Şimşek, M., 2005. Evidence and implications of massive erosion along the Strait of İstanbul (Bosphorus). Geo-Mar Lett. v. 25: 324-342. Doi: 10.1007/s00367- 005-0216-3.

13. Gökaşan, E., Algan, O., Tur, H., Meriç, E., Türker, A., Şimşek, M., 2005. Delta formation at the southern entrance of Istanbul Strait (Marmara Sea, Turkey): a new interpretation based on high- resolution seismic stratigraphy. Geo-Mar Lett. v. 25: 370-377. Doi: 10.1007/s00367-005-0215-4.
Published
2017-12-26
How to Cite
Toker, M. (2017). The Array Analyzing of The High Quality Glacial Seismic Events Active in Greenland Using Long-Period Surface (Rayleigh) Wave Detection by the German Regional Seismic Network. Hittite Journal of Science & Engineering, 5(2), 165-173. Retrieved from https://www.hjse.hitit.edu.tr/hjse/index.php/HJSE/article/view/HJSE19030000091
Section
ENGINEERING