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The Finite-Interval Spectral Power–A Tool for Identification of Underground Cavities

Session: Explosion Seismology Applications and Advances I

Type: Oral

Date: 4/19/2021

Presentation Time: 10:15 AM Pacific

Description: 

Undetected underground cavities of natural or artificial origin pose a serious geotechnical hazard. Detecting and locating underground cavities mainly in urban development and civil construction is therefore important for increasing human safety.

Underground cavities also arise due to underground nuclear explosions. Therefore, detection and location of a cavity generated by an underground nuclear explosion is an important proof in case of suspicion of violating the Comprehensive Nuclear-Test-Ban Treaty (CTBT), an international treaty banning nuclear weapon test explosion or any other nuclear explosion which is yet to come into force.

We have developed a new method for detecting and locating a horizontal position of an underground cavity. We have defined the Finite-interval Spectral Power (FISP) of seismic ambient noise. Mapping FISP makes it possible to identify the position of the cavity. The method can utilize single-station measurements at a set of potentially irregularly distributed points in the area on the Earth’s free surface over a suspected cavity.

Because the method gives better results for undistorted segments of noise records, we have also developed an automatic identification of such segments.

We validated our method using records of noise from a site near the Felsőpetény, Hungary, which were collected for the CTBT Organization during a field test in the framework of developing on-site inspection (OSI) capabilities. The method is ready for further tests in different cavity conditions and applications.

Presenting Author: Jozef Kristek

Student Presenter: No

Authors