An analysis of Receiver Operating Characteristic (ROC) curve on seismo-ionospheric precursors of the TEC in Taiwan

• Main Authors: Ai-Ling Shih, 石艾伶
• Other Authors: Jann-Yenq Liu
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/96907108150943642907

碩士 === 國立中央大學 === 太空科學研究所 === 104 === Receiver Operating Characteristic curve (ROC curve) be used to study seismo-ionospheric precursor (SIP) in Taiwan. A median-based method together with the z test is detected the relationship between ionospheric F2-peak plasma frequency foF2 and 50 M≥5.5 earthquakes, local GPS TEC (Total Electron Content) and 50 M≥5.5 earthquakes 1994-1999, and GIM (Global Ionospheric Map) TEC 129 M≥5.5 earthquakes 1999-2014 in Taiwan. First, it is calculated that move 15-day median, upper quartile and lower quartile for create the reference range of upper bound and lower bound. The anomalies are two result that increase (positive) anomaly and decrease (negative) anomaly. In total, z-test is found that 1-4 days and 23-28 days before earthquake are negative anomaly and negative anomaly, respectively. In detail, the results of foF2 show that negative anomaly is in period of 1200-2000 LT 1-3 days before earthquake 1994-1999. However, GPS TEC shows that negative anomaly is in 1400-1600 LT 2-4 days before earthquake 1994-1999, and GIM TEC shows that negative anomaly is in 1800-2200 LT 1-3 days before earthquake 1999-2014. For positive anomaly, foF2 shows that increase in 1300-1500 LT 15-17 days, GPS TEC increase in 1200-1400 LT 24-28 days, and GIM increase in 0900-1400 LT 23-28 days. Further, different reference days (7, 15, and 30 days before and after earthquake) find that 30-days period of positive and negative anomaly. ROC curve shows that SIP is confirmed since the area under the ROC curve is positively associated with the earthquake magnitude. In addition, p-value are approximately zero mean that SIPs are effective in Taiwan.