Latitude: N 34°00'23"N
Longitude: W 116°34'20"W
Number of Bench marks: 19
Number of Surveys to 2000: 6
Date of Initial Survey: 31 July 1992
Date of Latest Survey: 5 September 1996
Trespass Permission: Contact Caltrans
Directions: Proceed east on I-10 from San Bernardino toward the Coachella Valley. Exit north on to Hwy 62 toward Morongo Valley and Yucca Valley. Proceed 7.1 miles to Indian Avenue and exit right. Proceed about 100 m to dirt road that leads north parallel to Hwy 62 . The southernmost bench mark is in a large boulder in the northwest corner of the intersection of the dirt road and Indian Avenue, and the remaining of the line trends north and follows the fence between the dirt road and the highway.
Comments: This line was established across the Mission Creek fault following the 28 June 1992 Landers earthquake to measure vertical displacement. A strain quadrilateral was established nearby and shares bench mark MW08 with the level line. Bench mark MW18 was bent during a flood and was used instead as a temporary point in the September 1994 survey.
Four levelings are compared in the graph below. The basin side of the fault subsided a few millimeters relative to the mountain side between 1992 and 1996.
Clark, M. M., 1984. Map showing recently active breaks along the San Andreas fault and associated faults between Salton Sea and Whitewater River - Mission Creek, California. U.S. Geological Survey Map I-1483, 1:24,000.
Up one level
Return to the Title Page.