以時間域解迴旋分析近震源波形資料得到分布於2019年ML 6.3秀林地震周圍的視震源時間函數，並利用破裂方向性原理調查此地震的斷層參數。結果顯示秀林地震具有單向破裂的特徵，其破裂方向近似朝向正北，此確認一個東北-西南走向且向西傾的面是為斷層面，也得到其破裂長度約11.5 km，平均歷時7.37 sec(比震源時間函數的7.95 sec小一些)，顯示了破裂速度(Vr)約1.56 km/s，大約是0.4Vs (Vs為S波速度)，也相似於2018年花蓮地震(約0.55Vs)。震源時間函數亦顯示有兩個子破裂發生，破裂速度分別為1.61 km/s和1.48 km/s，與整體破裂速度相近；除外，兩個子破裂的Vr3乘積與整體破裂的DrVr^3近乎相同(Dr為靜應力降)，表示無論子破裂或整體破裂都顯示相同的破裂特徵。根據震源時間函數的頻譜分析，得到拐角頻率為0.099 Hz，進一步得到上揚時間為1.52 sec，約是整個歷時的0.19倍。
We used time-domain deconvolution to investigate the source time functions (STF) of the 2019 Xiulin earthquake, varying with the station azimuth. Through rupture directivity analysis, the earthquake is an event with unilateral faulting, and its fault parameters are obtained, including a rupture length of 11.5 km, a rupture direction of N5E, a rupture velocity of 1.56 km/s, and a source duration of 7.37 s, slightly smaller than that determined from STF. Then, the fault plane is also confirmed to be that with a west-dipping and near 200-strike plane. From the derived source time function, the earthquake rupture can be divided into two parts. The former has a rupture velocity (Vr) of 1.61 km/s, and the latter has a Vr of 1.48 km/s. The rupture velocities of the two sub-ruptures are similar to the average rupture velocity; in addition, there is also similar DrVr3 (Dr: static stress drop) whether it is derived from the average rupture or from the sub-rupture. From the source spectrum of STF, the Xiulin earthquake has a corner frequency of 0.099 Hz, leading to a rise time of 1.52 sec, about 0.19 times the value of the entire source duration.
