The occurring source of the strong SSW event had strong regional character. The northeast land of Europe-Asia was the region which strong SSW occurred most frequently.

强SSW事件发生源地有较强的地域性，欧亚大陆的东北部是发生源地最为频繁的地区。

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The Sichuan Yunnan region is one of the areas, where earthquake activity is strongest in the intra continent of China, and strong earthquake have occurred frequently in the recent years.

川滇地区是中国大陆内部地震活动最强的地区之一，且近期的强震活动仍十分频繁。

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