vectors from the central line of fault zone along two
sides of it can be calculated by integral. So we have
calculated out the crust movement vectors relative the
central line of fault belt in this area with GPS data in
different period, and Fig4 give us an example. In Fig
4a, the relative movement along two sides of
Xianshuihe fault zone is well balanced and expanded
from 2001 to 2004. It can explain why no strong
earthquake in a long period there although the fault
activities are remarkable. In Fig 4b, the increased
movement vectors are relative small, expanded in
north part and weakly compressed in south part. With
similar analysis for other faults in this area, it seems
no evidence to support a strong earthquake will
generate in this area in a short time after the great
earthquake in Indian Ocean.