coML

33.8965 deg N, 117.0866 deg W

The creepmeter is located near the northeast edge of Mystic Lake at the northern end of the San Jacinto Valley. A small-scale releasing
step-over along the Claremont fault has created a sag depression. Evidence for at least six surface ruptures is recorded in the stratigraphy of the past 1700 years.The fault trace was identified precisely from offset features visible in paleoseismic trenches on each side of the fault (excavated by Tom Rockwell and Sally McGill).

Download numerical data 15 Aug 2010 to Jan 2011.

Four columns CSV data suitable for Excel. Column 1 MLday date format MM/DD/YY space HH:MM:SS Column 2 MLDegC Column3 MLdextral slip in mm, column 4 MLV battery voltage

coML Mystic Lake

The creepmeter is 12 m long and is buried at a depth of 60 cm at 30 degrees across the Clairmont strand of the San Jacinto fault. THe lake floods after prolonged rain. The location was identified from offset features visible in paleoseismic trenches on each side of the fault (excavated by Tom Rockwell). The installation uses six 3 m deep steel piles driven into the lake clays. See installation report ,. The geological slip rate here is believed to be 10-20 mm/yr.

Data

Data are transmitted currently at 30 minute intervals. Since installation in August until the lake flooded on October 1 mm of dextral slip occurred (3.0 mm/yr). It is possible that the signal is contaminated by a seasonal thermoelastic strain although the initial month of data suggests that this is likely to be small. The damaged data logger will be replaced by a watertight system in the spring of 2011.