Anomalies of zenith tropospheric delay following the Mw 7.8 Haida Gwaii earthquake
Y. B. Yao1,2, X. X. Lei1, Q. Liu1, C. Y. He1, B. Zhang1, and L. Zhang11School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China 2Key Laboratory of Geospace Environment and Geodesy, Ministry of Education, Wuhan University, Wuhan 430079, China
Received: 16 Apr 2014 – Accepted for review: 30 Apr 2014 – Discussion started: 16 May 2014
Abstract. The 2012 Haida Gwaii earthquake was a massive Mw 7.8 earthquake that struck the Queen Carlotte Islands Region on 28 October 2012 (UTC). This study analyzed the variations in zenith tropospheric delay (ZTD) following the Mw 7.8 Haida Gwaii earthquake using near real-time ZTD data collected from eleven stations in the seismic region and the forecast ZTD of ECMWF. A new differential method was used to detect anomalies of ZTD time series. Result showed that obvious ZTD anomalies occurred on the day of the earthquake (day-of-year, doy 302). There were anomalous ZTD variations at eight stations in the post-earthquake period on doy 302, possibly due to the processes of earthquake-generated acoustic waves. Propagation of acoustic waves caused variations of tropospheric parameters (e.g., atmospheric pressure, temperate, and atmosphere density), thus influencing ZTD. Absence of anomalous ZTD variations at the remaining three stations was attributed to the special topographic conditions, i.e., the long epicentral distance and the presence of huge mountains as a natural protective screen. Our work provides new insights to the relationship between of earthquake event and ZTD variation. The proposed differential method is superior to conventional method for detecting specific ZTD anomalies caused by earthquake events.
Yao, Y. B., Lei, X. X., Liu, Q., He, C. Y., Zhang, B., and Zhang, L.: Anomalies of zenith tropospheric delay following the Mw 7.8 Haida Gwaii earthquake, Nat. Hazards Earth Syst. Sci. Discuss., 2, 3533-3559, doi:10.5194/nhessd-2-3533-2014, 2014.