coNR

36.8550 degN

121.5460 degW

The creep-meter was originally installed by Bob Nason in the 1960's as a crossed pair of 45 degree dial gage instruments. The site is frequently flooded and it has been found necessary to use a submersible data logging system to obtain data continuity.

The creepmeter crosses the San Andreas fault in the transition zone between the southern end of the 1906 rupture and the northernmost segment of the central California creeping zone. The fences and road at Nyland Ranch have been offset more than 40 cm by fault creep at a rate of 8-10 mm/yr. A buried water pipe was broken in September 2004 to the south of the road and a gas pipe to its north in Dec 2010.

Data

The mean rate of slip here is 8.7 mm/yr. Left lateral displacements occur in the rainy season which recover during dessication of the clay.