Talk:Toba catastrophe theory/Archive 2

Archive 1

Archive 2

No volcanic winter in East Africa - UNIVERSITY OF ARIZONA 50.252.107.21 (talk) 04:41, 7 February 2018 (UTC)

No volcanic winter in East Africa from ancient Toba eruption The supereruption 74,000 years ago did not trigger major environmental disruption that caused human populations in East Africa to decline, say University of Arizona geoscientists. UNIVERSITY OF ARIZONA https://www.eurekalert.org/pub_releases/2018-02/uoa-nvw020618.php

This confirms previous studies, but may be worth adding to the citations once the journal article is available. Dudley Miles (talk) 09:50, 7 February 2018 (UTC)

In the section Volcanic winter and cooling computer models it says "The Toba eruption apparently coincided with the onset of the last glacial period." The last glacial period started 110,000 years ago. What some scientists are claiming is that Toba triggered the onset of glacial stage MIS4 (lasted about 14,000 years) or GS-20 (glacial stadial) which lasted over a thousand years. Neither of these theories are generally accepted because the evidence is inconclusive. Among other things, the annual layer count in the ice cores only goes back 60,000 years. Zyxwv99 (talk) 23:57, 17 February 2018 (UTC)

I have deleted the incorrect statements, but as the theory is now generally dismissed, the whole article needs re-writing by an expert. Dudley Miles (talk) 00:16, 18 February 2018 (UTC)

Right. Like the problematic Younger Dryas impact hypothesis. Zyxwv99 (talk) 00:28, 18 February 2018 (UTC)

That is even more dificult. If I understand correctly, versions of it still have significant, though minority, support. Dudley Miles (talk) 09:56, 18 February 2018 (UTC)

Volcanic Winter

This statement is complete nonsense:

However, assuming an emission of six billion tons of sulphur dioxide, his computer simulations concluded that a maximum global cooling of approximately 15 °C occurred for three years after the eruption, and that this cooling would last for decades, devastating life. Because the saturated adiabatic lapse rate is 4.9 °C/1,000 m for temperatures above freezing, the tree line and the snow line were around 3,000 m (9,900 ft) lower at this time.

First of all, the saturated adiabatic lapse rate depends both on pressure and temperature and can be as high as close to 10°/km when the temperature is high enough, to as low as 4°/km around freezing with low pressure. Second, the average lapse rate of the atmosphere is not the same as the saturated adiabatic rate. Third, a tree line that is 3000m lower than usual will leave most of the Earth without any trees. Does anyone have any source for this statement? Mmom (talk) 21:33, 28 July 2019 (UTC)

The statement is sourced to this ref:

• Robock, A.; Ammann, C.M.; Oman, L.; Shindell, D.; Levis, S.; Stenchikov, G. (2009). "Did the Toba Volcanic Eruption of ~74k BP Produce Widespread Glaciation?". Journal of Geophysical Research. 114 (D10): D10107. Bibcode:2009JGRD..11410107R. doi:10.1029/2008JD011652.

A version I found here supports the idea that most trees (including nearly all broadleaf evergreen trees) were killed in the cooling. However the part about the lapse rate seems to be WP:SYNTHESIS and should probably be removed. Daß Wölf 03:07, 17 August 2019 (UTC)

Honorifics

There have been a number of flawed edits in respect of an honoric, such as [1]. These are in error as they breach MoS. Please review [2] — Preceding unsigned comment added by 2A00:23C5:9313:B900:C501:3B5E:927A:2FE8 (talk) 20:03, 19 January 2020 (UTC)