关键词: 短临异常, 异常时空演化, 震源硬化模型, 丽江地震

Abstract: During the short-term and impending predictions of Lijiang earthquake ,recognition of the characteristics of successional anomalies , new successional anomalies and new anoma­lies is discussed. Meanwhile, the criteria of anomalies entering the short-term and impend­ing phase,such as the ending of the medium-term anomalies,dramatic anomalies and syn chronous turning, of Lijiang earthquake is also discussed. Finally, based on discussion of time-space evolution of the short-term and impending anomalies, the author has presented a new focal seismogenic model-the focal hardening model.combining the facts mentioned in other papers ,such as anomalous quiescence of small earthquakes within epicentral area, the station-based precursory anomalies migrating from the periphery towards the epicen­ter, anomalies in the periphery having large amplitudes and quantity and so on. According to the model, the anomalous quiescence of small earthquakes should appear during the medium-and short-term phase within the epicentral area (aftershock-distributed or macro­fissure-distributed areas), and no or a few station-based precursory anomalies appear. However, when a strong earthquake is developed towards nucleation of fractures, that is the unreversible unstable phase, distinct macro-fissures probably appear in some focal ar­eas,namely sand-eruption and foreshock activity may appear.

Key words: Short-term and impending anomaly, Time-space evolution of anomaly, Focal hardening model, Lijiang earthquake