Let me give you a thought experiment. London and Siberia are 180 degrees apart in longitude. Do you really think it's the same distance in both directions? If you can't see that, consider any two points on the coastline of Antarctica that are 180 degrees of longitude apart.
I've already realised that I was being a pillock when I assumed that *all* places 180 degrees apart in longitude, *irrespective of latitude*, would have equal distances either clockwise or anticlockwise round the globe. The only time this would be true is for places that were at the same latitude but opposite sides of the equator (eg one at 20 deg N and the other at 20 deg south) with opposite longitude (eg 20 deg E and 160 deg W) - so the straight line joining them goes through the centre of the earth.
I've already worked out that Tonga and the UK are about 16500 km / 10000 miles apart by great circle, so the "round the back" route on the great circle is 40000-16500 = 23500 km (circumference of earth is about 40000 km). That would give transit times for the pulses by the two routes of about 15 and 22 hours if we assume speed of sound is about 300 m/sec, which agrees roughly with my weather station's pressure readings (1930 same day and 0200 next day, for eruption at about 0400 (all times GMT).
There is a longest *on a great circle*.
a slice through a sphere that intersects two points and the centre of a spere defines the great circle of those two points. It has two paths - the shortest and the longest that are 'straight' in one dimension.
Once you dimp straight there are an infinite number of infinitely long paths ...
That is my point really. The first blip is likely to be a great circle shortest path but after that who knows?
Both directions? Why are you only limiting direction of travel to due East or due West?
The first blip shows both positive and negative pressure, which is characteristic of an explosion. The second one appears to be most negative, which is why I wondered if it was the result of the ash column collapsing under its own weight and air rushing in to fill the space.
In a big eruption like this soluble fluoride toxicity is also a problem for many plants and animals. I expect that includes fish in close proximity and downwind of the ash clouds too.
It can also affect potable water supplies for humans and livestock.
Somehow it managed to get some superheated seawater trapped inside the rising magma and then it failed and blew off the volcano top completely. Similar mode of failure to Krakatoa and before that Toba. It may well mean that we get some spectacular sunsets and sunrises from stratospheric dust. The blast was powerful enough to inject some.
I expect subs would be OK they are designed to survive very high pressures anyway. Might be quite a loud bang inside the sub though! Fish would be killed/stunned out to some distance. Fishing with dynamite is considered unsporting but effective.
Back of the envelope a 50MT groundburst gets you a 10 mile diameter crater. That looks to be about right given the vanished island parts.
The shockwave did a couple of laps of the Earth and over peak pressure at a distance should be enough to get an independent estimate of the blast.
North and South. I took it as read that the OP would be taking great circles.
We're getting them now.
Bill
My problem with all of this is accepting that we live on a ball that's whizzing through space.
Bill
This effect is common on short wave (HF) radio. When propagation conditions were favourable I have heard Australian radio stations' signals arriving by both 'Short Path' and 'Long Path' simultaneously. This shows up as an echo of a few tens of milliseconds delay (the speed of light is obviously much greater than the speed of sound.)
I have even heard signals sent from the UK going right around the world and arriving back here 1/7th of a second later.
Does anyone believe anything the CCP says ?.
What aspect of that do you find most problematic?
Yes. It's been going on for a while as well.
Bill
Yes, they are clearly cracking down very heavily with the omicron infected.
Well, unless Brian was imagining it, why didn't it appear in other news agencies' reports? Whether it's true or not, it just seems strange that it has disappeared from the news. I'd have thought it was newsworthy, even if later it had been corrected as being untrue.
Ultra large explosive volcanic eruptions tend to produce enough stratospheric aerosols and dust to result in a couple of years of "nuclear winter" as their primary effect. The canonical event in that league in recent history was Mt Tambora in April 1815 which led to near global crop failures and the year without a summer.
Roughly causing a -3C shift in average global temperatures the following year. Europe and America both very badly affected.
Basaltic flood plains with a nice mobile liquid lava might release enough CO2 more quietly without too much aerosols to cause trouble by warming but it hasn't happened for a very long time. Short term the sulphur haze from vulcanism would take the edge off it but longer term the excess CO2 would win out.
ISTR Last time volcanic CO2 made a really big difference to the Earth's climate was when the Deccan traps were laid down in India 66My ago.
One way to ameliorate the problem of global warming as a solution of last resort is to provoke the Yellowstone caldera into a full eruption. It would destroy a rather beautiful national park and probably work but also render most of the Western USA uninhabitable.
In our lifetimes, it took about 10 years after the 1993 Mt Pinatubo eruption for the Earth systems to recover from the natural but "false" cooling after that eruption. There is no such thing as a free lunch though.
Looks like NASA assessed the Tonga eruption at 10 megatons of TNT, compared to Pinatubo and Krakatoa of 200 megatons , so I doubt its after-efects will be observable in the global geodata beyond 1 year timescale, if at all
And Tunguska was 20 Megatons (est)
It really puts the CND alarmists into perspective when one decent volcano can do far more damage than all the nuclear weapons in all the arsenals....
OTOH world annual energy consumption is around 133,000 megatons.Imagine having that stored in a fast release energy store, like a battery.. . And (I cant believe this) total sunlight that warms the world is only
633,000 megatons per year.Forget CO2....
It's obviously wrong. They reckon 4.3E+20 Joules per hour from the sun, about 100,000 megatons per hour.
So 1 hour solar is about equal to human energy usage for a year.
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