Mechanical strain gauge measurements at Te Marau
Abstract
In 1981 an array of five steel rods linking four monument
was installed across the trace of the Wellington Fault, at the site of the Te Marau water storage project. This array was instrumented with electronic displacement transducers and data loggers to serve as a horizontal strainmeter. Corresponding measurements have been made from time to time using a Whittemore mechanical strain gauge. Though these measurements are consistent with a model of right lateral shear deformation at an average rate of (5 ± 2) x 10-6 /yr (engineering units) since 1982, some or all of this estimate may be due to flexure of the rods; it may therefore be considered as an upper limit to deformation at the site. Verification by precise surveying methods may be possible if there is a sufficiently broad zone of deformation.