Revisiting the anomalous shelf water oscillation of Buckles Bay, Macquarie Island

Historic observations of sea-level on Macquarie Island recorded an ~6 min oscillation with a perceived beat of ~3h, interpreted as two counter-rotating edge waves of slightly different frequencies. Alternative evidence is presented here that the oscillations are consistent with the fundamental shelf period of Buckles Bay; an envelope characteristic of local coast and shelf features. New data from a shore-mounted tide gauge, analyzed using fourier and wavelet techniques, show an ~6:6 min phenomenon occurring in bursts every 1–4 h. A simple model shows that the fundamental resonant frequency may spread and comply with maximum and minimum coast and shelf features.