## 5 Discussion and Conclusions  
In the present research, seismic gaps are identified as the periods with no occurrence of \(M\geq\) 4.0 earthquake for d\(T\geq\) 400 days. After examining all records in the Sichuan-Yunnan-Tibet-Qinghai junction area on the southeastern margin of the Tibetan Plateau in 1970-2022, a total of six \(M\geq\) 4.0 seismic gaps are identified. Spatio-temporal images of the seismic gaps show similar characteristics and demonstrate spatial overlapping and statistical significance. The quiet periods of the six seismic gaps lie between 419 and 777 days (that is, 14-26 months). The average time is approximately 580 days (19 months). Their spatial dimensions and semi-major-axis directions (all in the NNW direction) are basically similar. The semi-major-axis and semi-minor-axis lengths are 880-1050 km and 500-570 km, respectively, with average values of approximately 987 km and 533 km, respectively. After each seismic gap ended, \(M\geq\) 6.7 earthquakes occurred either inside or at the margin of its spatial location. The correspondence rate is 100%. Five earthquakes occurred within the spatial location of the gap (83%), while one was at the margin (17%). Case analysis revealed that, for the study area, \(M\geq\) 4.0 seismic gap images are of high significance in predicting \(M\geq\) 6.7 strong earthquakes. Occurrence time prediction: If the time of seismic gap formation (\(T0=\) d\(T\) = 400 days) is taken as the start time of forecasting, and dynamic prediction is done at 100-day intervals, the seismic gap images can act as a predictive index on a time scale of about 1-0.5 years or less. Hypocenter prediction: It is within or at the margins of the spatial locations of the gaps, mainly inside and within the boundary of the western Sichuan block. Magnitude prediction: \(M\geq\) 6.7 strong earthquakes can be predicted. The above is the outcome of a retrospective statistical analysis of earthquakes, providing only a fundamental statistical understanding. Further testing is necessary to determine the practical effectiveness of the results in predicting future earthquakes. The concept of seismic gaps, analyzed and discussed in this study, refers to the occurrence of reduced minor earthquake activity around the hypocenter or a sudden decrease before a strong earthquake. This phenomenon is also known as seismic quiescence, indicating a change in the seismic activity within and around the hypocenter. Seismic quiescence preceding strong earthquakes holds the potential for facilitating medium and short-term earthquake predictions and is considered the most reliable precursor by seismologists, generating widespread attention [23; 24; 25; 26; 27; 28; 29; 30; 31; 32]. Seismic gaps are commonly attributed to variations in rupture strength within complex seismogenic faults. Initially, low-intensity fault zones experience small background earthquakes due to tectonic stress, while high-intensity fault zones become blocked, resulting in gaps in seismic activity. [PERSON] [33] proposed the earthquake asperity model, utilizing the bimodal distribution of sub-fault strengths. [PERSON] [34] suggested dilatancy hardening, and [PERSON] [24] linked seismic quiescence to stress relaxation related to precursory slip, to explain this phenomenon. [PERSON] [35] presented a model of an inhomogeneous strong body, considering differences and interactions of medium properties inside and outside the hypocenter, to elucidate the physical mechanisms behind abnormal seismic activity patterns (seismic gaps) preceding strong earthquakes. [PERSON] and [PERSON] [36] employed numerical computer simulations using a one-dimensional spring-block (Burridge-Knopoff) model to investigate the spatiotemporal distribution of earthquakes. They observed that the frequency of smaller events gradually increased before a main shock, but there were very few small events in close proximity to the epicenter. The presence and characteristics of this donut-shaped short-term quiescence depended on the extent of frictional instability in the model.