Environmental Effects on Broadband Seismic Noise: A Year-Long Assessment from Maitri Station, Dronning Maud Land, East Antarctica

Abstract We present a detailed year-long characterization of seismic noise at the Maitri station (MAIT) in East Antarctica, based on continuous three-component waveform data from 2023. Using probabilistic power spectral density and probability density function analysis, we assess spectral behavior across vertical (HHZ) and horizontal (HHN, HHE) components over a broad period range (0.1–100 s). The vertical component records the lowest noise in the microseism (1–20 s) and long-period (>20 s) bands, consistent with reduced tilt sensitivity and robust bedrock installation, whereas at short periods (<1 s) levels are comparable to or slightly higher than the horizontals. Seasonal and month-wise analyses reveal clear environmental modulation: microseism noise intensifies during December–June, with amplitudes increasing by up to ∼15 dB, consistent with reduced sea-ice extent and enhanced Southern Ocean wave activity, whereas long-period fluctuations correlate with temperature-induced strain and wind variations. Short-period noise remains at low levels, with only seasonal elevations linked to summer field activity, highlighting the lack of persistent anthropogenic noise. Across all components and frequencies, power spectral density levels remain bounded by global new high and low noise models, demonstrating the station’s high-fidelity performance. These results position MAIT as a benchmark site for polar seismic studies and inform strategies for future broadband deployments in extreme environments.