초록 ▼

An apparatus for measuring in situ stresses surrounding an active earthquake fault and forecasting shallow earthquakes includes a network of monitoring stations, each operating a respective borehole assembly for measuring in situ lateral stresses. The monitoring stations are arrayed along a recogniz

An apparatus for measuring in situ stresses surrounding an active earthquake fault and forecasting shallow earthquakes includes a network of monitoring stations, each operating a respective borehole assembly for measuring in situ lateral stresses. The monitoring stations are arrayed along a recognized fault plane and arranged to straddle the fault plane, so that lateral stress readings may be obtained throughout the ground media surrounding the fault zone. All of the monitoring stations communicate with a central data-gathering facility, so that real-time analysis of changes in lateral stress orientation and magnitude surrounding the fault zone may be undertaken, and the results used to forecast forthcoming seismic events. Each borehole probe assembly includes a trio of single fracture expansion probes operated periodically, reiteratively, and automatically to expand against the borehole wall and determine the principal maximum and minimum lateral stress vectors in the underground media. The assembly is suspended in the borehole by a wireline that provides electronic communications with a ground level monitoring station. Each probe assembly includes an anchor section that secures the assembly in the borehole at a selected and variable depth, and provides a stable base for a rotator section that rotates the expansion probes to any selected angle about the borehole axis. The ground level monitoring station includes a data communication link to transmit borehole data to a central office and to receive operational commands.

대표청구항 ▼

A system for predicting shallow earthquakes by monitoring earthquake-producing underground stresses surrounding an earthquake fault plane, including: a plurality of monitoring stations arrayed along said fault plane on opposed sides of said fault plane; each of said monitoring stations including a b

A system for predicting shallow earthquakes by monitoring earthquake-producing underground stresses surrounding an earthquake fault plane, including: a plurality of monitoring stations arrayed along said fault plane on opposed sides of said fault plane; each of said monitoring stations including a borehole extending to a depth within the depth window of observation, and borehole probe means adapted to reside in said borehole and reiteratively and periodically measure and resolve lateral tectonic stress vectors in the rock media surrounding said borehole; telecommunication means for transmitting the measurements of lateral tectonic stress vectors from said plurality of monitoring stations to a data collection center; and means for processing said measurements to monitor changes in the magnitude and direction of the lateral stress vector field surrounding the fault plane, comparing the lateral stress vector field to the intrinsic strength of the rock media materials and known geologic structure of the fault plane in quantitative terms, and indicating an impending occurrence of a major earthquake along the fault plane when said lateral stress vector field exceeds said intrinsic strength.