Latitude-Time Total Electron Content Anomalies as Precursors to Japan's Large Earthquakes Associated with Principal Component Analysis
Figure 4
(a) shows the latitude-time TEC records in Japan for 2004 (Unit: TECu). (b) shows 12 principal eigenvalues in 2004. Five larger principal eigenvalues are represented in May, September, October, November, and December in which seven earthquakes occurred on May 29, September 5, September 6, October 23, November 28, and December 6 (Table 1).
