Subproject I

Seismo-ionospheric and atmospheric precursors

National Central University Professor Jann-Yenq Liu

Liu et al. [2000] for the first time report SIPs in the ionospheric plasma frequency (or electron density) in ionograms recorded by a local ionosonde in Taiwan. Liu et al. [2001] pioneer applying SIPs in the GPS TEC associated with the 21 September 1999 Mw7.6 Chi-Chi earthquake. Following Liu et al. [2001], the temporal and spatial SIPs in the global ionospheric map (GIM) of the GPS TEC associated with the 26 December 2004 M9.3 Sumatra-Andaman Earthquake [Liu et al., 2010], the 12 May 2008 Mw8.0 Wenchuan earthquake [Liu et al., 2009], and the 12 January 2010 M7.0 Haiti earthquake are reported. Here, the approach of Sub-project I detecting temporal and spatial SIPs by the GIM TEC (later GIM developed by iSTEP-3 will be employed) and conducting a physics model simulation is presented with the 12 January 2010 M7.0 Haiti earthquake as an example. Note that in iSTEP-4 the physics model simulation will be routinely carried out by Main project, and a new data assimilation model will be conducted by Sub-project.

Subproject II

Seismo-lithospheric precursors

National Chung Cheng University Assistant Professor Chieh-Hung Chen

Sub-project II will focus on the SLPs related to surface deformation by GPS measurements and magnetic anomalies by magnetometers of the lithosphere. Frist, this sub-project will estimate areas of earthquake-related stress accumulation from ground-based GPS observations. Second, we would like to find out the relationship between earthquake magnitude and geomagnetic anomalies. Third, characteristics of seismo-EM signals from the geomagnetic field will be investigated, and a warning system will be developed by using EM waves with those determined characteristics to increase the monitor density via lower cost. Finally, we would like to expose the causal mechanism of seismo-electromagnetic anomalies to integrate seismo-anomalies between lithosphere, atmosphere, and ionosphere by using the analysis method mentioned above.

Subproject III

Statistics for earthquake hazard

National Central University Professor Yuh-Ing Chen

Sub-project III shall conduct a statistical analysis by applying z test and the Receiver Operating Characteristic (ROC) curve on the GPS total electron content to search for statistical evidences and find characteristics of SIPs of the world. Sub-project III also conducts statistical analyses on the temporal and spatial seismo-lithospheric, atmospheric, and ionospheric precursors observed by the Main project and Sub-projects I and II, and support the statistical references for the sub-projects identifying precursors of an event. Sub-project III would finally evaluate the earthquake hazard in a certain region during a time period based on some available characteristics of the temporal SIPs, such as the SIP strength and SIP occurrence time. Here, the approach of this sub-project is shown by examining the SIPs of 56 M≥6.0 earthquakes in China [Liu et al., 2013].

Publication

Liu, J. Y., Y. I. Chen, S. A. Pulinets, Y. B. Tsai, and Y. J. Chuo: “Seismo-ionospheric signatures prior to M≧6.0 Taiwan earthquakes”, Geophysical Research Letters, Vol. 27, pp. 3113–3116 (2000).

Liu, J. Y., Y. I. Chen, Y. J. Chuo, and H. F. Tsai: “Variations of ionospheric total electron content during the Chi-Chi Earthquake”, Geophysical Research Letters, Vol. 28, pp. 1383–1386 (2001).

Liu, J. Y., Y. I. Chen, C. H. Chen, C. Y. Liu, C. Y. Chen, M. Nishihashi, J. Z. Li, Y. Q. Xia, K. I. Oyama, K. Hattori, and C. H. Lin: “Seismo-ionospheric GPS total electron content anomalies observed before the 12 May 2008 Mw7.9 Wenchuan earthquake”, Journal of Geophysical Research, Vol. 114, A04320, doi:10.1029/2008JA013698 (2009).

Liu, J. Y., Y. I. Chen, C. H. Chen, and K. Hattori: “Temporal and spatial precursors in the ionospheric global positioning system (GPS) total electron content observed before the 26 December 2004 M9.3 Sumatra-Andaman Earthquake”, Journal of Geophysical Research, Vol. 115, A09312, doi:10.1029/2010JA015313 (2010).

Liu, J. Y., C. H. Chen, H. F. Tsai, and H. Le: “A Statistical Study on Seismo-Ionospheric Anomalies of the Total Electron Content for the Period of 56 M≥6.0 Earthquakes Occurring in China During 1998–2012”, Chinese Journal of Space Science, Vol. 33, pp. 258–269 (2013).