Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Seismological investigation of crack formation in hydraulic rock fracturing experiments and in natural geothermal environments. Progress report, September 1, 1975--August 31, 1976

Technical Report ·
DOI:https://doi.org/10.2172/7146683· OSTI ID:7146683
A variety of new seismological methods is being developed for determining the structure of a geothermal energy source region. In one approach, seismic signals generated in the source region are utilized by interpreting them in terms of the parameters of a seismic source model. For example, using a fluid-filled tensile crack driven by excess pressure in fluid as a model of volcanic tremor, formulas are derived which relate seismic observations with model parameters, and applied the formulas successfully to an actual eruption in Kilauea, giving a new insight to the magma transport in a volcano. Theoretical work is continued on the diffraction of seismic waves by a crack and it was demonstrated that the size and location of a crack can be well determined by particle motion near the crack at various frequencies. The method was applied to Kilauea Iki and the location of the magma lens was found to be in agreement with that estimated by another method. An extensive field experiment in Kilauea Iki was carried out with the cooperation of USGS and SANDIA, and interesting properties of the magma reservoir were revealed by a multiple use of active, passive, conventional, and unconventional seismic methods. The self-contained, digital event recorder has been developed and successfully tested.
Research Organization:
Massachusetts Inst. of Tech., Cambridge (USA)
DOE Contract Number:
EY-76-S-02-2534
OSTI ID:
7146683
Report Number(s):
COO-2534-2
Country of Publication:
United States
Language:
English