Yep she's a pretty stunning eruption. We heard it here in NZ as it was in Alaska. However what is unusual about it is the tsunami. It's not unusual for eruption induced local tsunami, but for a worldwide tsunami, that's quite rare. The most famous one is the Krakatoa one from 1883 and that has been theorised to have been the first recorded incidence of phase coupling between the atmospheric wave train and the tsunami wave train. If this is the case for the latest Tonga Hunga Tonga-Hunga Haʻapai eruption then it may explain why the tsunami reached so far.
However the real problem is that it is not known if this eruption is the end of this sequence, or just part of the current sequence. The question is whether or not this eruption is the largest of the sequence. The volcano has a history of explosive eruption sequences every 1,000 years. There is a massive caldera below the surface of the ocean that reaches to a depth of 150m Recent eruptions have formed the two islands.
Hunga eruption: Episode could last months, scientist says - NZ Herald
Why the volcanic eruption in Tonga was so violent, and what to expect next | Stuff.co.nz
Tonga tsunami, Hunga Tonga-Hunga Ha'apai eruption: Surging waves hit island nation - NZ Herald
Volcanic gases are now making their way around the Pacific. With the amount of gas and particles ejected into the stratosphere by the eruption there will be some climatic impacts possibly lasting the next 12 - 24 month period. There may be 1 or 2 cold years ahead depend upon how much SO2 (sulphur dioxide) that has been ejected. When SO2 interacts with atmospheric water (H2O) it forms H2SO4 (sulphuric acid) in the form of droplets. These are highly reflective, increasing the earth's albedo, reflecting solar radiation back into space. Those atmospheric acid droplets eventually fall as acid rain having detrimental impacts upon vegetation, runoffs, waterways and water storage.
Tonga volcano eruption and tsunami: Invisible and toxic gas currently over the Pacific - NZ Herald
Tonga eruption likely the world's largest in 30 years - scientist | RNZ News
There are reports of a British aid worker missing on the main island of Tongatapu.
Tonga volcanic eruption: Fears for missing British aid worker Angela Glover - NZ Herald
EDIT: Add Radio NZ Link.