Measurement and Analysis of ground movement using microgeodetic networks on active faults

Abstract

Repeated geodetic surveys over a thrust fault in the Peruvian Andes, demostrate surprisingly little movement in spite of continued low level seismicity. The inexpensive rugged instrumentation used can achieve accuracies of better 5 x 10^-6 in strain. Reduction of the survey data to show movements of points could be replaced by strain analysis but probably should provide a direct connection to fault split. Linears system analysis provides an alternate method of reduction whose theory is developed here but whose practice is more complex than expected.