Fig. 1From: A confirmation of vertical acoustic resonance and field-aligned current generation just after the 2022 Hunga Tonga Hunga Ha’apai volcanic eruptionGeomagnetic field variation at Apia and Honolulu. The upper 4 traces are the variations after baseline subtraction and the lower 3 traces shows the high-pass filtered data. Note that the D-component of Honolulu data are converted to nT unit in approximately eastward positiveBack to article page