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Posted: Tue Sep 04, 2007 4:53 pm
by Beagle
Even the Mt. St. Helen eruption shot ash into the statosphere, and by a year later had circulated it around the globe. And that was a small eruption.

Posted: Tue Sep 04, 2007 5:01 pm
by Digit
Agreed Beag, but did the ash circulate in one direction or both?

Posted: Tue Sep 04, 2007 7:00 pm
by Beagle
I don't know what happened here Digit, but the end of the conversation is in the Global Warming thread. :?

Posted: Wed Sep 05, 2007 7:00 am
by Roberto
http://en.wikipedia.org/wiki/Lake_Toba

By reading this informatioM it helps to understand the previous article on
Mt. Toba's eruption. :wink:

Now read this info on Krakatoa which erupted in 1883. Historical records record the catastrophic effects. Note, Mt. Toba is noted as a VIP (volcanic eplosion index) #8, and Krakatoa was a VIP #6.

http://en.wikipedia.org/wiki/Krakatoa

Read the Global Climate and Legacy of 1883 Eruption sections.
Projection of ash into the stratosphere carried it around the world, effecting the climate for several years. The stratosphere carried it around
the world, westward. While local fall out and winds below the stratosphere moved ash eastward. Same thing with Mt. Toba I would expect.

Very interesting thing about Krakatoa was that the world discovered that a seismic wave could be felt around the world, just from one large volcanic eruption. It was a scientific break through that evolved into what we know about seismic waves todays.

CHEERS .... :wink:

Posted: Wed Sep 05, 2007 7:12 am
by Digit
I've read all this before Rob, and once again I find myself studying what is not said. How do they explain a bottleneck caused by a climate change that isn't supported in their idea by a matching one in other species.
I find myself repeating the same mantra as earlier.
Possible, but unlikely.

Posted: Wed Sep 05, 2007 7:51 am
by Roberto
What I read out of the article was that Petraglia ("07) appears to have "sunk" the Toba Bottleneck Theory entirely. He showed that life went on after the eruption, just like before with modern humans using the Middle Stone Age Tradition, and not Neantherhals. Modern humans survived in the area maintaining the same gene pool.

As far as the migration route perspective, unless they have bone material for DNA studies, it will always be debated until more evidience is found.
Archaeological material in stratigraphic context and DNA studies of skeletal material might sign some light on the subject.... perhaps.

Posted: Wed Sep 05, 2007 7:54 am
by Digit
Makes you ask why people promote theories with such obvious defects in them doesn't it?

Posted: Wed Sep 05, 2007 10:13 pm
by daybrown
Castledon says that mt Stronghyle, on Thera, blew 6 times stronger than Krakatoa. Dunno how that compares to mt Toba. but 1628 BC seems to coincide with the rise of the Shang. Anyone got any info on what it may have done to the Indus?

I can see where the ash on the fertile crescent mite've been a problem, but since that agriculture was irrigated, weather changes would not have been such a biggie.

Seems like there was a revolution at Carcal Peru in this era too.

Posted: Wed Sep 05, 2007 10:43 pm
by Minimalist
Digit wrote:Makes you ask why people promote theories with such obvious defects in them doesn't it?
Too narrow a focus? We need a few renaissance men looking into this.

Posted: Fri Sep 07, 2007 1:56 pm
by Beagle
Anyone got any info on what it may have done to the Indus?
At about the same time that volcanic activity was going on in the Med., the area of the Indus/Sarasvati civilization underwent tectonic activity. The result of the earthquakes was the gradual drying up of the Sarasvati river. And that resulted in the decline of the whole civilization.

So, yeah, pretty serious time for a lot of areas.

Posted: Sun Jan 20, 2008 12:52 pm
by Beagle
http://news.bbc.co.uk/2/hi/science/nature/7194579.stm

Scientists have found what they say is the first evidence of a volcanic eruption under the Antarctic ice sheet.

They believe the volcano erupted about 2,000 years ago, and would have burst through its ice covering, producing a burst of steam and rocky debris.

The British Antarctic Survey (Bas) scientists report their finding in the journal Nature Geoscience.

They say it could aid understanding of an ice mass which is likely to play a key role in climate change.
This is not Mt. Erebus, which is the world's largest volcano, but one just discovered.

Posted: Sun Jan 20, 2008 1:04 pm
by Cognito
Even the Mt. St. Helen eruption shot ash into the statosphere, and by a year later had circulated it around the globe. And that was a small eruption.

Agreed Beag, but did the ash circulate in one direction or both?
Beags, I was living near Seattle at the time it blew. The ash traveled east with the prevailing weather. After the eruption Seattle received a very light ash dusting a couple of times when the winds shifted -- nothing significant.