This was the largest volcanic outburst in 140 years.
Rumblings started on December 18, 2021, beneath the Kingdom of Tonga's tiny South Pacific islands of Hunga Tonga and Hunga Ha'apai.
It was 10 times the force of Mount St. Helens on Jan. 15th.
A 30 km-high umbrella cloud with a brief "overshoot" emerged.
After a 2015 eruption, ash and magma filled the gap between the two Hunga islands.
After January's explosion, the newer centre portion sank, separating unoccupied Hunga Ha'apai and Hunga Tonga.
Lamb waves are pressure waves of atmospheric fluid caused by volcanic eruptions and nuclear testing.
A ship undergoing maintenance might be decommissioned in 2023.