DIRECTFLT wrote:

I wish the NZ or Aust. Govt. would parachute drop in a squad to asses what's going on on the main Island.

NZ is sending HMNZS Aotearoa, HMNZS Wellington has already left, she has onboard, divers, a survey team and a helicopter.

https://youtu.be/0nUe8Aggc-Y

Tonga is a lovely country that is very close to my heart.

The west side of Tongatapu (where the resorts are--resorts being locally owned and operated small hotels) has been badly damaged. We're hearing that most of the properties close to the beach are completely gone, including the place I got married. The good news is all the people from Ha'atafu escaped and are safe. They lost everything, though.

Two islands close to the volcano in the Ha'apai group were devastated: one island had all structures destroyed, another had all but two. Population of the first island was about 500. The Ha'apai group is also a beautiful area and extremely low lying.

No damage reports from Vava'u yet, but there are also basically no communications from there. Vava'u is hillier overall, though, and would likely be less affected.

'Eua also has reports of some damage, with a few houses destroyed.

Texan

Here's a link detailing Texan's post about heavy damage on three of Tonga's Islands. I fear more bad news to come as communication with Tonga is re-established:

https://www.adn.com/nation-world/2022/0 ... feet-high/

StarAC17 wrote:

For Volcano geeks.

The full movie is on YouTube. This is a Canadian/British docudrama on what a Yellowstone super eruption would do to the US and the world.

It's a full out movie but factual.

https://youtu.be/WFaFfdOzPP8

ssteve wrote:

BN727227Ultra wrote:

Hunga-Tonga-Hunga-Ha’apai! Preliminary interpretations of satellite data by educated hobbyists suggest it might be as big as Pinatubo in 1991. I could imagine US West Coast-AU/NZ might be affected as well as regional.

Potentially two years of cooler temperatures if it's Pinatubo sized.

It was a VEI 5. Equivalent to Mt. St. Helens. It might drop temps 0.1-0.2 degrees C. I have to remember where I read that. It also depends on how much Sulfur Dioxide was in the eruption. That is the gas that reflects sunlight.

Pinatubo was a VEI 6.
Like the Richter scale each jump represents a 10 fold increase of material ejected. It was 10x the strength of Mt. St Helens.

Mt. Tambora which caused the year without a summer in 1813-1814 IIRC was a VEI 7. 10 times Pinatubo at minimum.

Sorry, VEI5? Just because of the loud bang and the big eruption cloud? The loud bang and the big cloud cab be explained by the suden contact of the lava with water, so the big cloud is just steam and not material.
Till now, it is best case just a VEI4. Seems to be less than 0.4 km3 of material (Tephra), around 400.000 t of SO2; this is a VEI4.
VEI5 is regular more than 1 km3 tephra as example.

T4thH wrote:

StarAC17 wrote:

For Volcano geeks.

The full movie is on YouTube. This is a Canadian/British docudrama on what a Yellowstone super eruption would do to the US and the world.

It's a full out movie but factual.

https://youtu.be/WFaFfdOzPP8

ssteve wrote:

Potentially two years of cooler temperatures if it's Pinatubo sized.

It was a VEI 5. Equivalent to Mt. St. Helens. It might drop temps 0.1-0.2 degrees C. I have to remember where I read that. It also depends on how much Sulfur Dioxide was in the eruption. That is the gas that reflects sunlight.

Pinatubo was a VEI 6.
Like the Richter scale each jump represents a 10 fold increase of material ejected. It was 10x the strength of Mt. St Helens.

Mt. Tambora which caused the year without a summer in 1813-1814 IIRC was a VEI 7. 10 times Pinatubo at minimum.

Sorry, VEI5? Just because of the loud bang and the big eruption cloud? The loud bang and the big cloud cab be explained by the suden contact of the lava with water, so the big cloud is just steam and not material.
Till now, it is best case just a VEI4. Seems to be less than 0.4 km3 of material (Tephra), around 400.000 t of SO2; this is a VEI4.
VEI5 is regular more than 1 km3 tephra as example.

Just going with what I read but if your numbers are right then yes VEI 4.

https://www.volcanocafe.org/the-vei-5-m ... nga-tonga/

This website says VEI 5. Wikipedia says borderline VEI 4 to VEI 5

https://en.wikipedia.org/wiki/2022_Hung ... nd_tsunami

StarAC17 wrote:

T4thH wrote:

StarAC17 wrote:

For Volcano geeks.

The full movie is on YouTube. This is a Canadian/British docudrama on what a Yellowstone super eruption would do to the US and the world.

It's a full out movie but factual.

https://youtu.be/WFaFfdOzPP8



It was a VEI 5. Equivalent to Mt. St. Helens. It might drop temps 0.1-0.2 degrees C. I have to remember where I read that. It also depends on how much Sulfur Dioxide was in the eruption. That is the gas that reflects sunlight.

Pinatubo was a VEI 6.
Like the Richter scale each jump represents a 10 fold increase of material ejected. It was 10x the strength of Mt. St Helens.

Mt. Tambora which caused the year without a summer in 1813-1814 IIRC was a VEI 7. 10 times Pinatubo at minimum.

Sorry, VEI5? Just because of the loud bang and the big eruption cloud? The loud bang and the big cloud cab be explained by the suden contact of the lava with water, so the big cloud is just steam and not material.
Till now, it is best case just a VEI4. Seems to be less than 0.4 km3 of material (Tephra), around 400.000 t of SO2; this is a VEI4.
VEI5 is regular more than 1 km3 tephra as example.

Just going with what I read but if your numbers are right then yes VEI 4.

https://www.volcanocafe.org/the-vei-5-m ... nga-tonga/

This website says VEI 5. Wikipedia says borderline VEI 4 to VEI 5

https://en.wikipedia.org/wiki/2022_Hung ... nd_tsunami

Regarding of the size/heigh of the plume and loud bang, we have here perhaps even a VEI6 or even higher, so a VEI7, if we would have here not a special case, that there was a sudden water /lava explosion, So it is easily to be overestimated regarding the bang and the size of the plume. Much steam and "low" anount of tephra (0.4 km3 is not really low, it is still a big amount).
400.000 t of SO2 has been already measured and calculated by the NASA and other scientist, also this fits more to a VEI4. A 30 km high plume? This fits to VEI7.

If less than 0.4 km3 tephra and 400.000 t of SO2, it fits pretty well to the 2021 eruption of the La Soufriere, ca. 0.3 to 0,35t km3 tephra and 400.000 t of SO2. This was VEI4.

My understanding is that the main eruption was astonishingly violent but also astonishingly brief, only about 10 minutes.
So huge in peak power, but not overly large in material ejected.
That is to date, we don't know what it still has in store.

DIRECTFLT wrote:

I wish the NZ or Aust. Govt. would parachute drop in a squad to asses what's going on on the main Island.

Tonga has remained covid free by strict border controls.
The absolute last thing it wants is to deal with a covid outbreak in parallel with the aftermath of a volcanic eruption and tsunami.
Hence the delay in Tonga approving the arrival of NZ and Australian military supply vessels and aircraft until protocols for contactless deliveries and tasks were agreed.
The NZ Naval vessels have divers onboard to survey the seabed on approach to, and against the wharfs before ships come alongside.
They can accomplish this task without contact with locals.
Air deliveries will be land, unload onto the tarmac for Tonga to uplift from the tarmac.
I imagine sea deliveries will be the same.

VEI= Volcano Explosivity Index. Has nothing to do with the volume of ejected material, just how much of a BOOM there was. There's a big discussion on the site that I follow--has been for some time but Saturday made it more intense--about the limitations of the VEI. it doesn't handle effusive eruptions well, such as Laki in 1783 or Mayotte in 2018-2019.

Massive Tonga underwater volcano 3-D imaging

https://twitter.com/jamaicanrabbit5/sta ... 7285905409

Here are a couple of before/after shots from the west coast of Tongatapu, of what used to be the Ha'atafu Beach Resort where I got married. Pictures sent from the resort owners, who escaped by climbing up a mango tree with their children and being rescued by some neighbours. According to them, the tsunami came out of nowhere as the eruption (at least sound/sight of it) hadn't reached Ha'atafu by the time the first tsunami waves did.

Texan

HOLY COW ! ! ! I feel very sorry for those affected, and it seems as if many, many were affected, even though the megablast occurred in a remote part of Oceana. So, how big was the blast? Even the experts are having trouble getting their minds and their arms around it. But, with all of the sensors on Earth and the satellites above it, we will be learning a lot about this eruption long after you and I are gone! (I'm just a young buck of 65.)

Dr. Carl Rehnberg has posted an excellent article on the Volcano Cafe website. He has a gift for being able to make technical information interesting, and comments to his article--with more information in real time--are coming in fast and furious. He calls the blast a "supercriticality event". Here is a link to it . . . https://www.volcanocafe.org/hunga-tonga ... ity-event/

If we had only known ahead of time that this was going to happen!