Session Description: Large eruptions at Hunga Tonga-Hunga Ha'apai on both 14 and 15 January 2022 produced plumes that reached the stratosphere and caused significant regional disasters by volcanic ash and tsunamis. It also triggered atmospheric pressure waves that were observed globally. The infrasound signals even produced seismic signals that are stronger than the surface wave from the eruption itself. The tsunami was also recorded globally, starting immediately after the pressure waves but earlier than expected arrival times of tsunamis. The earthquake and/or its underwater landslides broke undersea communication cables further impacting Tongan society. Reports on interdisciplinary aspects of this volcanic eruption, atmospheric, ocean waves and solid earth, as well as disasters they caused are welcome.