地震為臺灣地區常見的天然災害之一，通常是由斷層的活動造成，而要如何有效地預測地震及降低災害的損失是非常重要的課題，因此從70年代初期開始，各國的科學家們就已經開始嘗試用各種方法來進行地震之預報。先前許多文獻指出，在地震發生前，地表溫度會出現異常的現象，而衛星遙測可應用熱紅外影像來反演地表溫度，得到大範圍的地表溫度變化，進而預測地震的發生，具相當潛能。因此，本研究將基於斷層帶地區的地表溫度變化，嘗試歸納斷層活動與地表溫度變化的相關性。由於地表溫度變化細微，需要高時間及高空間解析度的衛星影像資料，透過自適應時空反射率融合模式 (Spatial and Temporal Adaptive Reflectance Fusion Model, STARFM)，將向日葵衛星8號 (Himawari-8) 及大地衛星8號 (Landsat-8) 兩顆不同優勢的衛星影像進行融合，獲得高時空融合影像的地表溫度資訊。搭配中央氣象局地震測報中心的地震活動資料，選用芮氏規模大於4，震度4級以上的地震資料，其中以兩種不同的地震狀況當作案例分析，並藉由地表平均溫度 (地表均溫) 得到地表溫度異常 (熱異常)，針對花蓮地區的斷層，進行地震前後，斷層上熱異常現象之分析與探討。研究結果顯示，地震發生前幾天，斷層上會出現熱異常現象，而且震度越大，地表溫度變化 (攀升) 越明顯。從單一地震來看，震度4級的地震，各斷層上的地表溫度大約上升1~2度；從地震群來看，由於連續地震的影響，各斷層上的地表溫度會上升並維持在相對高值，地震結束後，地表溫度便趨於正常。藉由本研究之個案分析，說明了高時空解析地表溫度 (熱異常) 之變化可應用於斷層活動之分析。;Earthquakes are one of the common natural disasters in Taiwan, usually caused by fault activity. How to effectively predict earthquakes and reduce disaster losses is a crucial issue. Therefore, since the early 1970s, scientists from various countries have begun to try to predict earthquakes with various methods. Many previous literatures pointed out that Land Surface Temperature (LST) will be abnormal before earthquakes. This research uses thermal infrared images to retrieve LST, and attempt to analyze the correlation between fault activity and LST anomalies. Due to the subtle LST anomalies, satellite image data with high spatial and temporal resolution is required. Through the Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM), the two satellite images of Himawari-8 and Landsat-8 with different advantages are fused to obtain the high spatial and temporal resolution LST image. This study collected the seismic activity data from the Seismological Center of the Central Weather Bureau. The thermal anomalies of 6 faults in Hualien area are analyzed and discussed before and after the earthquake. The result indicated that the thermal anomalies occurred on the fault before the day of earthquake, and the bigger the earthquake, showed the temperature rise more obvious. From the perspective of single earthquake, an earthquake with four degree of seismicity, the LST will increase about 1 to 2 degrees. From the perspective of earthquake swarm, due to the effect of consecutive earthquakes, the LST of the fault will keep in a higher value before the ending of fault activity. The results of case studies point out that the LST anomaly in high spatiotemporal resolution can be applied to the researches related to the fault activities.
