由於地震是一最不可預測的天災，又其帶給的傷害相當大，所以關於如何
預測及地震前兆成為一項非常重要的課題。兩個在大地震來臨之前的前兆現
象－地震寧靜、地震活化，通過對此兩前兆現象之觀察，或許可進而偵測到
大地震之來臨。所謂地震寧靜：如同其字面意思，在大震來臨之前地震活動
度平均降低，低過整個地震活動度的背景值，這樣的現象乃來自於能量在這
段時期的累積，累積的期間由於沒有釋放出來因此也較少地震產生；相對地，
當能量累積的越多所需時間越久，呈現出的寧靜亦越大，隨之而來的地震也
越大－如同在一些真實地震中看到的現象一樣。在一些研究中，由於地震寧
靜可以指出地震活動度異常的時間及地區而幫助成功預測大地震即將來臨。
地震寧靜與地震活化是一體兩面的，地震活化通常伴隨了地震寧靜而來；這
是一種能量的高級相變，通過了地震活化的轉移，能量達到臨界點釋放而形
成大地震。在針對集集作為例子所用的統計方法－RTL（Region-Time-Length）
演算法中清楚得到了地震活動度在時間上的變化，也確實發現在像集集地震
這樣的特徵地震之前有一段維持長達2～3 個月的寧靜期，隨後而來的是一段
地震活化時期。將寧靜時間主要活動度變低的時間取出作二維分布圖時尚可
發現這些寧靜都發生在集集震央附近；活化時期也可窺見高地震活動度環繞
在集集震央附近。RTL 演算法要有效表示出地震寧靜及地震活化尚且需除去
特徵時間、特徵長度等不安定因素，因為人為選取以上自由參數可能造成RTL
不客觀結果，因此在本研究中更利用計算RTL 間之相關係數取得最佳自由參
數。而最後的結果亦証明了相關係數的演算更完善了RTL 演算法。從前人的
研究及此次研究的結果可以更加確信地震寧靜的偵測，或許將可給予在地震
預測上極大的幫助。

By means of the Region-Time-Length (RTL) algorithm, which is widely used
for investigating the precursory seismicity changes in China, Italy, Japan, Russia
and Turkey, we examine the precursory seismic activity occurred prior to the 1999,
Mw = 7.6, Chi-Chi earthquake around its epicenter. Based on our calculation of the
RTL values, the epicentral area has been found to strongly exhibit the signature of
anomalous activity, associated with the seismic quiescence and activation, before
the main shock. Also proposed in this study is a helpful method for determining
two important parameters used in the RTL analysis, the characteristic time and
distance. Such method will largely reduce the ambiguity in the original RTL
algorithm. The RTL results made from the catalogs with different magnitude range
show that earthquake quiescence should be influenced not only by intermediate
magnitude earthquakes, but also by smaller earthquakes. The relationship that the
RTL value correlated with the square and cube of number of earthquakes implies
that the RTL value is not just simply guided by the earthquake number. For testing
the statistical significance of our result, we got a probability of 2% of the
quiescence anomaly and of 0.5% when constrained that the anomaly occurred 2.5
years before the large Chi-Chi earthquake. We thus proved that the quiescence
before Chi-Chi earthquakes is not resulted from the stochastic process.

Bak, P., and C. Tang, 1989. Earthquakes as a self-organized critical phenomenon, J. Geophys.
Res., 94, 15,635-15,637.
Bak, P., Tang, C. and Wiesenfeld, K., 1988. Self-organized criticality, Phys. Rev., A 38,
364–374.
Bonilla M.G., Mark R.K. and Lienkaemper J.J. 1984. Statistical relations among earthquake
magnitude, surface rupture length, and surface fault displacement, Bull. seism. Soc. Am., 74,
2379–2411.
Bowman, D. D., and G. C. P. King, 2001. Accelerating seismicity and stress accumulation before
large earthquakes, Geophys. Res. Lett., 28, 4039–4042.
Bowman, D. D., G. Oullion, C. G. Sammis, A. Sornette, and D. Sornette, 1998. An observational
test of the critical earthquake concept, J. Geophys. Res., 103, 24,359– 24,372.
Brehm, D. J., and Braile, L. W.,1998. Intermediate-term Earthquake Prediction Using Precursory
Events in the New Madrid Seismic Zone, Seis. Soc. Am. Bull. 88, 564–580.
Brehm, D. J., and Braile, L. W., 1999. Intermediate-term Earthquake Prediction Using the
Modified Time-to-failure Method in Southern California, Seis. Soc. Am Bull. 89, 275–293.
Chen, C., 2003. Accelerating seismicity of moderate-size earthquakes before the 1999 Chi-Chi,
Taiwan, earthquake: testing time-prediction of the self-organizing spinodal model of
earthquakes. Geophys. J. Int., 155: F1～F5.
Di Giovambattista, R. and Tyupkin, Yu.S., 2000. Spatial and temporal distribution of seismicity
before the Umbria-Marche September 26, 1997 earthquakes, J. Seismology, 4, 589-598.
Hainzl, S., G. Zöller, and J. Kurths, 1999. Similar power laws for foreshock and aftershock
sequences in a spring-block model for earthquakes, J. Geophys. Res., 104, 7243-7254.
Hainzl, S., G. Zöller, and J. Kurths, 2000. Seismic quiescence as an indicator for large
earthquakes in a system of self-organized criticality, Geophys. Res. Lett., 27, 597–600.
Huang, Q. and Nagao, T., 2002. Seismic quiescence before the 2000 M = 7.3 Tottori earthquake,
59
Geophys. Res. Lett., 29(12), 1578, doi:10.1029/2001GL013835.
Huang, Q., 2004. Seismicity pattern changes prior to large earthquakes-An approach of the RTL
algorithm, Terrestrial, Atmospheric and Oceanic Sciences, 15, 469-491.
Huang, Q., Oncel, A.O. and Sobolev, G.A., 2002. Precursory seismicity changes associated with
the Mw = 7.4 1999 August 17 Izmit (Turkey) earthquake, Geophys. J. Int., 151, 235-242.
Huang, Q., Sobolev, G.A. and Nagao, T., 2001. Characteristics of the seismic quiescence and
activation patterns before the M = 7.2 Kobe earthquake, January 17, 1995, Tectonophysics,
337, 99-116.
Huang, Q. and Sobolev, G.A., 2001. Seismic quiescence prior to the M = 6.8 Nemuro Peninsula
earthquake, Proc. Japan Acad., 77, 1–6.
Iida, K., 1965. Earthquake magnitude, earthquake fault, and source dimensions. J. Earth Sci.
Nagoya University, 13, 115± 132.
Lee, C.P. and Tsai, Y.B., 2005. A study of recurrence models of earthquakes in Taiwan,
Terrestrial, Atmospheric and Oceanic Sciences, 16, 251–271.
Reasenberg, P., 1985. Second-order moment of central California seismicity, 1969-1982, J.
Geophys. Res., 90, 5479.
Rundle, J.B., Klein, W., Turcotte, D.L. and Malamud, B.D., 2000. Precursory seismic activation
and critical-point phenomena, Pure appl. Geophys., 157, 2165–2182.
Sobolev, G.A. and Tyupkin, Y.S., 1997. Low-seismicity precursors of large earthquakes in
Kamchatka, Volc. Seis., 18, 433–446.
Sobolev, G.A. and Typukin, Yu.S., 1999. Precursory phases, seismicity precursors, and
earthquake prediction in Kamchatka, Volc. Seis., 20, 615-627.
Tinti, S. and Mulargia, F., 1985. Completeness analysis of a seismic catalog, Annales
Geophysicae 3(3), 407–414.
Tocher D. 1958. Earthquake energy and ground breakage. Bull. Seism. Soc. Am., 48, 147-153.
Turcotte, D. L., 1999. Seismicity and Self-organised Criticality, Phys. Earth Planet Int., 111,
60
275–293.
Varnes, D. J., 1989. Predicting Earthquakes by Analyzing Accelerating Precursory Seismic
Activity, Pure appl. geophys. 130, 661–686.
Varnes, D. J., and Bufe, C. G., 1996. The Cyclic and Fractal Seismic Series Preceding an mb 4.8
Earthquake on 1980 February 14 near the Virgin Islands, Geophys. J. Int. 124, 149–158.
Wang, J.C. and Shieh, C.F., 2004. Investigation of seismicity in central Taiwan using the
accelerating seismic energy release model, Terrestrial, Atmospheric and Oceanic Sciences,
15, 1–13.
Wells, D.L. and Coppersmith, K.J., 1994. New empirical relationships among magnitude, rupture
length, rupture width, rupture area, and surface displacement, Bull. seism. Soc. Am., 84(4),
974–1002.
Wyss, M., and R. Dmowska (Eds.), 1997. Earthquake prediction – state of the art, Pageoph
Topical Volumes, Birkhäuser, Basel.
Wyss, M., and R. E. Habermann, 1988. Precursory seismic quiescence, Pure Appl. Geophys.,
126, 319-332.
Zoller, G., Hainzl, S., Kurths, J. and Zschau, J., 2002. A systematic test on precursory seismic
quiescence in Armenia, Natural Hazards, 26, 245-263.