Tonga volcano.

[SkidsFox]

Looks fairly huge. 

[moore_94]

 

[SkidsFox]

They heard it in New Zealand ffs.

[Steve_Guppy_Left_Foot]

Makes you think how small we all are, it's crazy. 

[st albans fox]

19 minutes ago, SkidsFox said:

They heard it in New Zealand ffs.

Did they actually hear it or was it just the shock wave ??

 

would be astonishing for the sound to travel that far and be audible to humans …

[MPH]

Tsunami hit after

[SkidsFox]

6 minutes ago, st albans fox said:

Did they actually hear it or was it just the shock wave ??

 

would be astonishing for the sound to travel that far and be audible to humans …

Ah

Quote

Local forecaster Weather Watch tweeted about the eruption: "The energy release is simply astonishing", adding: "Reports of people hearing the sonic booms across New Zealand."

 

https://www.bbc.co.uk/news/world-asia-60007119

[Spiritwalker]

6 minutes ago, st albans fox said:

Did they actually hear it or was it just the shock wave ??

 

would be astonishing for the sound to travel that far and be audible to humans …

They just showed some news footage from 500miles away and there was a very loud bang.

[Finnegan]

2 hours ago, st albans fox said:

Did they actually hear it or was it just the shock wave ??

 

would be astonishing for the sound to travel that far and be audible to humans …

 

They heard it in Fiji apparently. 

[StanSP]

Some of the satellite images and visuals are ridiculous. 

 

 

 

 

 

 

 

[AS78UK]

https://theconversation.com/why-the-volcanic-eruption-in-tonga-was-so-violent-and-what-to-expect-next-175035 good article on it. 

[leicsmac]

6 hours ago, Steve_Guppy_Left_Foot said:

Makes you think how small we all are, it's crazy. 

And yet, a glance at the Covid thread (and one or two others) indicates that some people still think what humans do to each other is a bigger threat than what the earth can do to us.

[Smudge]

1 hour ago, leicsmac said:

And yet, a glance at the Covid thread (and one or two others) indicates that some people still think what humans do to each other is a bigger threat than what the earth can do to us.

'Some' people will always have a divergent view on everything, don't you think?

Edited 16 January 2022 by Smudge

[leicsmac]

2 hours ago, Smudge said:

'Some' people will always have a divergent view on everything, don't you think?

Absolutely, and that's fine.

 

It's when that viewpoint manifests itself in action (or lack thereof) regarding natural events that things might become problematic. I think it's a reasonable assumption that many people lost a lot regarding Covid because they or other people downplayed the threat, and look at what we're (not) doing regarding climate change.

 

When it comes to events like this, acting as one species rather than fighting among ourselves will simply save lives, livelihoods and misery.

[SpacedX]

15 hours ago, st albans fox said:

Did they actually hear it or was it just the shock wave ??

 

would be astonishing for the sound to travel that far and be audible to humans …

Good point.

 

Humans interpret pressure waves through a medium as sound.They're sound waves but not truly. Sound waves are caused by oscillations of pressure in the air. Audible sound is therefore limited by the size of this oscillation of air pressure presenting a natural limit to how loud sound can get. Because of this, the loudest (sustained) sound possible is a pressure wave oscillating between vacuum and +2 atmospheres and equates to 194 decibels. The amplitude of the wave is capped so no sound on earth (at sea level) can exceed this. You can have shock waves that are bigger than 2 atmospheres, which theoretically have have a higher decibel number than 194dB, but this is not a sustained audible sound.

 

Beyond 194 decibels there is no more air to pressurise at that point, and the rarefaction (the negative cycle of a given waveform) is actually 'clipped' in 1 atmosphere - creating a vacuum. The launch of the Saturn V measured 220 decibels at the pad, (and had to be protected by an attenuation system/water suppression (900,000 gallons of it dumped on the pad). But as it rose from the tower this 'clipping' created a “crackling” effect caused by the sound waves compressing the air they’re traveling through to maximum allowed by physics - and when the sound travelled further away from the launch pad and the pressure front collapsed it registered as a series of snaps. 

 

Sperm Whales are the loudest animal on earth whose clicks can achieve 233 decibels. Water is a very good propagator of sound which travels five times faster than in air. Some estimations have suggested their communication can reach up to 10,000 miles.

 

The loudest sound in recorded history came from Krakatoa in 1883. The explosion was reportedly heard 4800 km (3000 miles) away, where people described the sound as cannon fire from a nearby ship and I think the pressure waves travelled seven times round the globe. 

 

I was reminded yesterday, that as a kid living in North Shore Auckland, we were issued a Tsunami warning and advised to head for higher ground inland following an earthquake in Tonga. Ironic that some of the high ground in the city is a consequence of it being built over a volcanic field itself. 

 

EDIT TO ADD: There are conversely many sounds that are inaudible to the human ear but nonetheless present. Infrasound - the span of low-frequency sounds below 20 Hz and the crowd at Craven Cottage for example. 

Edited 16 January 2022 by Line-X

[SkidsFox]

Could be a couple of cooler summers ahead, depending on what's in the Ash and how much of it. Get your holiday in early this year?

[SpacedX]

2 minutes ago, SkidsFox said:

Could be a couple of cooler summers ahead, depending on what's in the Ash and how much of it. Get your holiday in early this year?

There are many variables at work here. In 2019, the VEI 5/6 monstrous eruption of Shiveluch on the Kamchatka peninsula caused huge stratospheric injection - lofting some 768Gg of sulphate mass up to 12 miles into the atmosphere. Volcanoes produce between 65 and 120 million tonnes of sulphate aerosols per year. It's the Tambora scale events that result in the years without a summer, though as I recall, Mt St Helens made for some vivid sunsets!

[StanSP]

Erupted again?! 

 

Not sure if this is footage of the original one or the reported new one today 

 

 

 

[leicsmac]

https://www.bbc.com/news/science-environment-60019423

 

Better understanding through science and technology!

[ozleicester]

Absurd that our beaches in Australia were "closed" due to threat of Tsunami... people on the streets fighting for  a dickhead tennis players rights... ignores that we are not allowed to go to the beach.

Fear is taking over society