Por: A. Ambros y M. Döring, Institute of Mine Seismology, Ottawa, Canada.

Abstract

Mining waste by-products, known as tailings, are commonly stored in large-scale tailings storage facilities (TSFs) for extended periods of time. Tailings dams are among the largest human-made earth structures, making their stability critical to global mining operations. 

Several high-profile tailings dam failures, including the Brumadinho disaster in 2019, have made it clear that, despite these structures being carefully constructed and equipped with various instruments, such as piezometers, water quality probes, radars, cameras, and inclinometers, internal changes may go unnoticed until visible signs (such as seepage or vegetation anomalies) appear at the surface. 

Recent advances in ambient noise interferometry offer a promising approach for detecting these hidden internal changes. By analyzing continuous background seismic noise recorded by multiple sensors, this technique can reveal subtle variations in wave velocity and attenuation within the dam structure, as well as early indicators of the development of weaknesses or seepage pathways, long before they become visible at the surface. 

This study presents a two-year geophysical monitoring project conducted at the TSF complex of the Granny Smith mine in Western Australia. Seismic velocity variations over time were compared with observed precipitation and temperature data in order to investigate changes in the TSF conditions.