| 摘要: | 地震的發生仍未有效預測，其伴隨的災害易導致生命和財產損失，尤其淺源地震為首要關注之目標，為了減少地震災害的發生。地震預警系統( Earthquake Early Warning, EEW)是目前可以有效及時給予警訊的方法。其核心目標為在破壞性地震波(S波)到達前提供城市地區警報。由於台灣特別的震央分布與強震網的位置，此系統能提供數秒至數十秒之警報時間，對於事先準備之緊急應變系統而言數秒之警報時間十分重要。
本研究使用台灣自由場強地動觀測計畫( Taiwan Strong Motion Instrumentation Program, TSMIP)自1991~2013年之間的淺源地震事件分別進行地震預警系統(Wu et al., 2005, Wu et al., 2006, 蔡克銓等人, 2009)兩種不同，且對於全台灣地區地震資料建置之預估模型(W05, NCREE)，進行估算規模和震源距，分析觀測與預估間之差異。由於EEW系統提供預警大多是以震度為基準，但震度無法很精確地描述地動大小，因此本研究目的將其最終結果設定以PGA作為預估之標準。本研究發現利用Wu( 2005)的Pd和PGV關係式更進一步分析，可以建立宜蘭地區之Pd和PGA關係式，根據上述兩種模式分別進行單站場址修正，其修正後所估算之誤差明顯較低。
最後本研究利用兩筆目標地震進行兩種模型之實測，結果皆顯示針對W model加上單站修正，其誤差相對於其他方法最小，其即時預估結果較佳，可實際應用。
;Occurrence of earthquakes still could not effectively be predicted. The accompany disasters were easy resulting loss of lives and properties. Especially shallow earthquake should be taken more attention. In order to reduce disaster occurred for earthquake, it is an effective way that earthquake early warning (EEW) system can be applied for rapid strong motion prediction. The main target of EEW is to provide alerts to urban areas of the forthcoming strong ground shaking. Depending on the specific geometry of the epicenter and the strong motion network used in EEW Taiwan, the warning time can be a few seconds to tens of seconds. This warning time can be extremely important since even a few seconds can be sufficient for pre-programmed systems to have emergency response.
In this study, we use the shallow earthquake event which record by TSMIP from 1991 to 2012, we estimates magnitude and hypocenter distance with two kinds of prediction model based on regional Taiwan data (W05 and NCREE) for EEW systems (Wu et al., 2005, Wu et al., 2006, Tisa et al., 2009). Due to EEW system had selected intensity to provide warning now, but intensity could not accurately describe ground motion level. In this case, the purpose of this study will set focus on estimating PGA. The results showed the estimation could get formula of Pd and PGA for Ilan area based on relation of Pd and PGV (Wu et al., 2005). Next individually calculating site correction term for each station were applied to above mentioned two models.
Finally, the correction process of two different models applied to two target earthquakes in this study. The result indicated W model with site correction for each station had best prediction and lowest error related to other method. Which means the rapid estimation result base on site correction be widely applied. |
