Fig. 2From: A confirmation of vertical acoustic resonance and field-aligned current generation just after the 2022 Hunga Tonga Hunga Ha’apai volcanic eruptionEnlarged plots of high-pass filtered geomagnetic components. An oscillation at Apia start around 04:21 UT, about 7 min after the start of eruption. Although the amplitude is small, coherent oscillations with those in Apia encircled by orange and green dotted lines are observed at HonoluluBack to article page