Sources of seismic noise in an open-pit mining environment

Area of Science:

• Geophysics
• Mining Engineering
• Environmental Science

Background:

• Open-pit mines generate significant seismic noise from various sources.
• Tailings dams require continuous monitoring to manage increasing waste volumes and ensure stability.

Purpose of the Study:

• To characterize vibration sources at the Riotinto mine using a dense seismic network.
• To analyze seismic data for monitoring dam construction and tailings deposition processes.

Main Methods:

• Deployment of a 30-station seismic network over a 1-km segment of the tailings dam.
• Detection and classification of transient seismic signals (earthquakes, blasting, vehicles).
• Analysis of time variations in the 10-40 Hz frequency band amplitudes.

Main Results:

• Identified and differentiated seismic signals from local/distant earthquakes, blasting, and vehicles.
• Defined three distinct phases of seismic activity based on amplitude variations.
• Observed highest seismic amplitudes during five weeks of civil works for dam regrowth.
• Found that tailings deposition dominated seismic noise in the final three months, enabling detailed process monitoring.

Conclusions:

• Seismic monitoring effectively characterizes vibration sources in mining environments.
• Tailings deposition is a major contributor to seismic noise, providing a means for monitoring its evolution.
• The study demonstrates the utility of seismic data for operational monitoring in tailings dam management.