Detecting buried fault structures by microtremor survey method

The methods and schemes of detecting buried fault structures using microtremor survey method are introduced, by which two branch faults of the Tanlu fault zone are explored. Comparison with the shallow seismic exploration results indicates that the spatial locating ability of microtremor survey method is better to detect the buried fault structure, the location error of fault caused by lithological differences is close to that from the results of the shallow seismic exploration. For its deep exploration ability, the microtremor survey method can reveal the spatial distribution characteristics as well as contact relationship between the strata and the faults beneath the microtremor survey arrays, which is important to identify and confirm the main rupture surface of faults. However, the microtremor survey method is difficult to reveal or describe the detail features of faults. To explore the strata or faults, it is the best to combine the shallow seismic exploration method with the microtremor survey method to study the relationship between deep and shallow faults. The microtremor survey method can be used to detect fault roughly, and then the shallow seismic method can be used to determine accurate position of faults after knowing the general location and spatial characteristic of faults.