  The subsequent series of responses to big events may exhibit a synchronicity
of event number, frequency and energy release in different fault zones. This
synchronicity is a reliable source for probing non-intuitive geological
structures, assessing regional seismicity hazard map and even predicting the
next big events. The synchronicity of main faults in the eastern margin of the
Qinghai-Tibetan Plateau is still unknown to us. We propose to examine the
correlation of earthquake occurrence among different fault zones to indicate
this synchronicity, and to obtain a preliminary understanding of geodynamics
processes and the unrecognized characteristics of deep evolution in the eastern
margin of the Qinghai-Tibetan Plateau. We estimate temporal changes of
completeness level, frequency seismicity, and intensity seismicity, referring
respectively to Mc, Z, and E values, of 21 main fault zones, using a seismic
catalogue from 1970 to 2015. Our results reveal that six fault zone pairs of
fault zones exhibit relative high correlation (>0.6) by all three indicators,
while four fault zone pairs are non-adjacent with close internal affinity
offsetting the limit of spatial distance, such as the pair of Rongjing-mabian
fault and Minjiang-huya fault. Most strikingly, some fault zone pairs showing
typical high correlation (>0.8) of seismicity frequency or seismicity
intensity, the faults surprisingly belong to neither the same seismic belt nor
the same geological block, exhibiting a regional scale remote triggering
pattern of earthquakes or structures. An embryonic pattern to predict the next
possible events will also be presented. This correlation analysis discovers a
previously unrecognized strong coupling relationship among main faults with
high earthquake risk in the eastern margin of the Qinghai-Tibetan Plateau.
