台灣位處於太平洋西岸板塊碰撞的地震帶上，地震發生頻率高、強度大，易造成生命財產的損失。地震的發生是由於地殼內應變能量蓄積至其所能承受的限制時，地殼會產生突發性的斷裂與錯動，進而引發地震。在這突發性破壞現象之前，會先發生各種不同的物理或化學現象異常變化的徵兆，例如：地傾斜、地殼變形、地面隆起、地應力異常變化、地下水位變化、地下水顏色及化學成分含量改變、動物異常、氣象異常、氣溫改變、土壤溫度改變、地電、地磁、重力異常、有地鳴、地熱等。眾多方法中，遙測領域裡可以應用熱紅外線影像對地表溫度做監測，找出是否有大範圍增溫，以預測地震的發生，此方法的優點在於：衛星影像取得容易、資料收集方便、且遙測影像可以獲得大範圍面積的資料，而大規模的地震易牽涉到很大範圍的地區出現異常現象。從研究及文獻中也發現，地震前熱異常現象可能為最早出現的徵兆，如果能先掌握熱異常現象，則可以做為其他前兆偵測預警的機制，提升其他徵兆監測及地震預報的效果。本研究首先從文獻探討熱異常現象可能的發生機制及修改前人(Panda et al.,2007)研究的偵測方式，利用台灣地區已發生過大規模淺層強震(M>5)案例進行評估。在此研究中我們使用MODIS (Moderate Resolution Imaging Spectroradiometer)影像作為研究資料，並改善了前人析地表溫度變化的方法。藉由未發生地震活動的日期資料建立出適合的背景資訊，以利於觀察同時態上地震造成的溫度差異。我們總共分析了近十年發生在台灣地區附近的淺層強震，希望能藉由對地表溫度變化的時空分析，累積更多對於地震前兆現象的觀察、紀錄、分析與探討。以利未來能對此異常現象進行監測，進一步運用於嚴謹精確的地震預報工作中，提供社會大眾高品質的地震預報。 實驗結果顯示，多數的地震在發生日的前3-7天就會開始出現短暫的地表溫度攀升情形(熱紅外異常增溫的機制)，並在地震結束後開始降溫恢復平穩狀態。When earthquakes happen, the Earth’s crust will release energy. Therefore, the abnormal temperature rise may portend future earthquakes. In many ways, the telemetry field can applied thermal infrared images to monitor surface temperature to know if there is a wide range of warming for predict the occurrence of earthquakes. The advantages of this method are the satellite images data is easy to access, and remote sensing imagery can obtain information on large area. The large scale earthquake prone a wide range of areas to show an anomaly. Some research and literature also found that the thermal anomaly before the earthquake may be the earliest signs. If we can grasp the thermal anomaly before earthquake, we may establish early warning mechanisms to enhance the earthquake forecast.In order to gain an insight into the fact whether the existence of pre-earthquake abnormal temperature increase is a stable phenomenon, and also to detect this portend (for pre-earthquake abnormal temperature increasing phenomenon) in more scientific way, this thesis will first review literature documentations to investigate into the possible mechanism of thermal anomalies. This research will also adopt methods proposed by Ouzounov and Freund (2004) to conduct an evaluation of those large-scale strong earthquakes (M>5), aiming to find out the best process to detect the abnormal temperature increasing portend before strong earthquakes happened. The data used in this thesis is MODIS Land Surface Temperature and Emissivity (MOD11A1). The result of this research shows: the pre-earthquake abnormal temperature can be detected by thermal infrared satellite images. By spatial and temporal analysis of surface temperature change, and to accumulate more knowledge to observe, analyze and explore for earthquake precursory phenomena. To facilitate future of this anomaly monitoring, and further used in a rigorous and accurate earthquake prediction work. We hope to provide the high quality large earthquake prediction in the community.
