Measurement of seismometer misorientation based on P-wave polarization: application to permanent seismic network in South Korea

다국어 초록 (Multilingual Abstract)

Reliable information on the horizontal orientation of a seismometer is crucial to seismological research utilizing threecomponent seismograms. In this study, we provide misorientation angles of broadband seismometers in three permanent networks in South Korea from 2003 to 2021 by using two methods, denoted as PPCA and PminT, both utilizing P-wave polarization characteristics. Our estimates show that 36% of the sensors have been aligned within 5° from the geographic north during their operation periods, while 40% of the sensors have been rotated by more than 10° at least once. The estimates are highly consistent for both methods, with 95% of the total showing uncertainty less than 10°. Moreover, we identified a significant number of temporal changes in misorientation by taking automatic change point detection and visual inspection. The procedure described here and misorientation angles can be useful reference for seismic data preprocessing for research utilizing horizontal-component seismograms for earthquake sciences.

참고문헌 (Reference)

1 박동희 ; 조성일 ; 이용희 ; 최원학 ; 이동훈 ; 김학성, "원자력발전소의 부지감시시스템의 운영과 활용" 대한자원환경지질학회 51 (51): 185-201, 2018

2 이혜원 ; 신동훈, "시추공 지진계의 방위각 결정에 관한 연구" 대한지질학회 51 (51): 93-103, 2015

3 이상준 ; 이준기, "배경잡음 교차상관을 이용한 국내 광대역 지진계의 방위각 보정값 측정" 한국지구물리.물리탐사학회 18 (18): 85-90, 2015

4 임호빈 ; 김영희, "국내 지진계의 센서 기기 응답" 대한지질학회 56 (56): 515-524, 2020

5 신진수 ; 신인철 ; 신동훈, "국내 시추공 지진관측소의 방위각 보정" 대한지질학회 45 (45): 47-54, 2009

6 Kennett, B. L. N., "Traveltimes for global earthquake location and phase identification" 105 : 429-465, 1991

7 강태섭 ; Chang-Eob Baag, "The 29 May 2004, Mw=5.1, offshore Uljin earthquake, Korea" 한국지질과학협의회 8 (8): 115-123, 2004

8 Lim, H., "The 2017 Mw 5. 5 Pohang earthquake, South Korea, and poroelastic stress changes associated with fluid injection" 125 : e2019-, 2020

9 Woo, J. U., "The 2016 Gyeongju earthquake sequence revisited : aftershock interactions within a complex fault system" 217 : 58-74, 2019

10 Kim, W. Y., "The 20 January 2007 Odaesan, Korea, earthquake sequence : reactivation of a buried strikeslip fault?" 100 : 1120-1137, 2010

11 김영희 ; 이준기 ; 강태섭 ; 김광희 ; 김민욱 ; 이상준, "The 12 September 2016 Gyeongju earthquakes: 1. Observation and remaining questions" 한국지질과학협의회 20 (20): 747-752, 2016

12 Xu, H., "Systemic comparison of seismometer horizontal orientations based on teleseismic earthquakes and ambient-noise data" 108 : 3576-3589, 2018

13 Braunmiller, J., "Sensor orientation of Iranian broadband seismic stations from P-wave particle motion" 91 : 1660-1671, 2020

14 Zhu, H., "Seismic structure of the Changbai intraplate volcano in NE China from joint inversion of ambient noise and receiver functions" 124 : 4984-5002, 2019

15 Wang, X., "Seismic sensor misorientation measurement using P-wave particle motion : an application to the NECsaids Array" 87 : 901-911, 2016

16 Truong, C., "Ruptures: change point detection in Python"

17 Niu, F., "Receiver function study of the crustal structure of the southeastern Caribbean plate boundary and Venezuela" 112 : B11308-, 2007

18 Scognamiglio, L., "Real-time determination of seismic moment tensor for the Italian region" 99 : 2223-2242, 2009

19 Eisermann, A. S., "Real-time back azimuth for earthquake early warning" 105 : 2274-2285, 2015

20 Pearson, K., "Principal components analysis" 6 : 559-572, 1901

21 Jurkevics, A., "Polarization analysis of three-component array data" 78 : 1725-1743, 1988

22 Scholz, J. R., "Orienting ocean-bottom seismometers from Pwave and Rayleigh wave polarisations" 208 : 1277-1289, 2017

23 Büyükakpınar, P., "Orientations of broadband stations of the KOERI seismic network(Turkey)from two independent methods : P-and Rayleigh-wave polarization" 92 : 1512-1521, 2021

24 Rueda, J., "Orientation analysis of the Spanish Broadband National Network using Rayleigh-wave polarization" 86 : 929-940, 2015

25 Killick, R., "Optimal detection of changepoints with a linear computational cost" 107 : 1590-1598, 2012

26 Doran, A. K., "Ocean-bottom seismometer instrument orientations via automated Rayleigh-wave arrival-angle measurements" 107 : 691-708, 2017

27 Ekström, G., "Observations of seismometer calibration and orientation at USArray stations, 2006–2015" 108 : 2008-2021, 2018

28 Beyreuther, M., "ObsPy : a Python toolbox for seismology" 81 : 530-533, 2010

29 Zahradník, J., "Moment tensor resolvability : application to southwest Iberia" 102 : 1235-1254, 2012

30 Zeng, S., "Measurements of seismometer orientation of the first phase CHINArray and their implications on vector-recording-based seismic studies" 111 : 36-49, 2020

31 Ekström, G., "Measurements of seismometer orientation at USArray transportable array and backbone stations" 79 : 554-561, 2008

32 Lim, H., "Measurement of seismometer orientation using the tangential P-wave receiver function based on harmonic decomposition" 212 : 1747-1765, 2018

33 Liu, K. H., "Making reliable shear-wave splitting measurements" 103 : 2680-2693, 2013

34 Laske, G., "Frequency-dependent polarization measurements of long-period surface waves and their implications for global phase-velocity maps" 84 : 111-137, 1994

35 Kim, S., "Forward waveform modelling procedure for 1-D crustal velocity structure and its application to the southern Korean Peninsula" 185 : 453-468, 2011

36 Ojo, A. O., "Estimations of sensor misorientation for broadband seismic stations in and around Africa" 90 : 2188-2204, 2019

37 Ensing, J. X., "Estimating the orientation of borehole seismometers from ambient seismic noise" 109 : 424-432, 2018

38 Kim, Y., "Earthquake source mechanism and rupture directivity of the 12 September 2016 Mw 5. 5 Gyeongju, South Korea, earthquake" 107 : 2525-2531, 2017

39 Korea Meteorological Administration, "Earthquake Annual Report. Korea Meteorological Administration"

40 Zha, Y., "Determining the orientations of ocean bottom seismometers using ambient noise correlation" 40 : 3585-3590, 2013

41 Zhu, G., "Determining the orientation of ocean-bottom seismometers on the seafloor and correcting for polarity flipping via polarization analysis and waveform modeling" 91 : 814-825, 2020

42 Stachnik, J. C., "Determination of New Zealand ocean bottom seismometer orientation via Rayleigh-wave polarization" 83 : 704-713, 2012

43 Herrmann, R. B., "Computer programs in seismology : an evolving tool for instruction and research" 84 : 1081-1088, 2013

44 Niu, F., "Component azimuths of the CEArray stations estimated from P-wave particle motion" 24 : 3-13, 2011

45 Xu, W., "Comparing orientation analysis methods for a shallow-water ocean-bottom seismometer array in the Bohai Sea, China" 110 : 3174-3184, 2020

46 Kim, K. H., "Assessing whether the 2017 Mw 5. 4 Pohang earthquake in South Korea was an induced event" 360 : 1007-1009, 2018

47 Harris, C. R., "Array programming with NumPy" 585 : 357-362, 2020

48 Aminikhanghahi, S., "A survey of methods for time series change point detection" 51 : 339-367, 2017

49 Zheng, H., "A new method to estimate ocean-bottom-seismometer orientation using teleseismic receiver functions" 221 : 893-904, 2020