Latitude: N 34°16'34"
Longitude: W 117°28'00"
Length: 1169.7m
Number of Bench marks: 33
Number of Surveys to 2000: 7
Date of Initial Survey: 18 July 1985
Date of Latest Survey: 22 July 1994
Trespass Permission: Permission to trespassis required from property
owner.
Directions:
From the intersection of Interstate 15 and Hwy 138, take I-15 south 0.5 mile
to Cleghorn Road turnoff. Follow Cleghorn to the south (on the frontage road)
1.9 miles to Swarthout Canyon Road, thence right (west) and follow the road
to the left, cross the r ailroad tracks. At a point 0.8 mile from the tracks
(?) bear to the right at a "Y" in the road. Cross the tracks again and the
paved road will become a dirt road. At 0.7 mile from the second track cross
ing, proceed northwest on a dirt road that leads to the right. At 0.25 mile
from the right turn, over the fault scarp and on top of a river terrace,
is the beginning of the level line. The first bench mark is LL01.
Comments:
This is a box-shaped array across the San Andreas fault 100 m northwest of
Lost Lake and 2 km south of Cajon Junction, in Cajon Pass.
Results:
Three levelings of the array are compared in an accompanying graph. Bench
marks southwest of the fault and along Swaggart Canyon Road, spec ifically
from LL16 to LL22, have risen a couple of millimeters relative to those in
the remainder of the array, but the uplift is still within one standard deviation
of the allowable uncertainty
Up one level
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