台灣位處環太平洋地震帶，地震活動甚為頻繁。全球定位系統（GPS）被使用來測量集集大地震震央附近的永久地表位移，GPS技術能夠提供精確的量測位移值，但只有用在靜態測量才有好的結果。
另一方面，強震站藉著地震的發生並配上高取樣率可以偵測到地表的動態運動。台灣的中央氣象局已經廣泛的配置超過800個強震儀測站，其中一部份在集集地震附近的測站獲取了地震資料。
本研究呈現了分析加速儀資料後的結果，加速儀資料被積分得到在地震發生期間的速度和位置變化。並且，最小平方法被應用來估測存在於加速儀資料和速度中之定值的誤差。
本研究也比較了以GPS技術和加速儀分別得到在垂直和水平方向的解，發現靠近震央附近的永久位移的大小和方向都一致，這顯示出本研究所採用的方法適宜處理加速儀資料。從加速儀資料得到隨時間變化的解描述地表的動態運動，也顯示出大部分的永久位移在地震發生的100秒內就出現了。

Taiwan locates in a tectonic boundary that has many earthquakes occurred. A Global Positioning System (GPS) campaign was performed to survey the permanent surface displacement near the Chi-Chi earthquake epicenter. GPS technique is capable of providing accurate displacement measurement but is only good for static surveying.

On the other hand, the strong-motion station can sense the dynamic surface motion by earthquake with high sampling rates. The Central Weather Bureau (CWB) of Taiwan has been operating an extensive array of more than 800 strong-motion accelerograph stations. A part of the array around the Chi-Chi earthquake captured the earthquake sequence.

This study presents the results from analyzing the accelerograph data. The data was integrated to obtain the velocity and position changes during the earthquake. In addition, a least-squares method was applied to estimate the constant biases embedded in data and in velocity.

The comparisons in vertical and horizontal directions between the GPS and accelerograph solutions have been performed. It is found that the permanent displacements close to the earthquake epicenter agree in magnitude and direction. It indicates that the adopted method is suitable for processing the accelerograph data. The time history from the accelerograph solutions describes the dynamic motion of surface motion. It shows that most of the permanent displacements occurred in 100 seconds after the epic epoch

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[18]中央研究院郭隆晨博士