jump to navigation

Chaitén bulletins: no. 109 (30 October 2009) and no. 110 (13 November 2009) 24 November 2009

Posted by admin in activity reports, Chaitén, Chile, eruptions.
Tags: , , , ,
comments closed

In a remarkable development, SERNAGEOMIN has just released not one but two Chaitén bulletins to the public. Now available on the OVDAS ‘informes’ page are Chaitén bulletins 109 (PDF here, covering 16-30 October) and 110 (PDF here, covering 31 October to 13 November). Translations as follows.

16-30 OCTOBER 2009

1. Visual monitoring

During this period the volcano has remained obscured and only occasionally on 25 and 30 October has it been possible to observe the dome complex and its column of gas and ash. In general, the base of the column has appeared much wider, although the altitude has not exceeded 1.5 km above the domes (Fig. 1).

Chaiten 30 October 2009
Fig. 1. View from the DGAC camera in Chaitén on 30 October.


Toba eruption deforested India 24 November 2009

Posted by admin in climate, current research, India, Indonesia, Toba.
Tags: , , , ,
comments closed

The Toba eruption of ~73000 years ago is perennially fascinating: the world’s largest known Quaternary eruption, this event registered VEI=8 and had a global climatic impact that may have caused the near-extinction of humanity by creating a ‘population bottleneck’ (or perhaps not). The scientist behind the population bottleneck theory, University of Illinois anthropology professor Stanley Ambrose, is a lead author for a new study in the journal Palaeogeography, Palaeoclimatology, Palaeoecology (click here for the abstract) which explores further the impact of the Toba eruption and concludes that its effects were indeed wide-ranging and (crucially for the claim that contemporary human populations were dramatically affected) long-lasting.

The study looked at pollen from a marine core taken in the Bay of Bengal which includes ash from the Toba eruption and at carbon isotope ratios in fossil soil carbonates from directly above and below the Toba ash in three locations in central India. Both analyses indicated a change in the vegetation cover in central India after the Toba eruption, from forests to more open vegetation conditions with a predominance of grasslands. The change in vegetation suggests that significantly drier conditions were produced by the Toba eruption, and that those conditions lasted for at least a thousand years.

  • Martin A.J. Williams, Stanley H. Ambrose, Sander van der Kaarsc, Carsten Ruehlemannd, Umesh Chattopadhyayae, Jagannath Pale & Parth R. Chauhanf, Environmental impact of the 73 ka Toba super-eruption in South Asia, Palaeogeography, Palaeoclimatology, Palaeoecology [article in press, corrected proof], doi:10.1016/j.palaeo.2009.10.009 (abstract)

Supervolcano eruption – in Sumatra – deforested India 73,000 years ago – EurekAlert, 23 November 2009
Supervolcano eruption in Sumatra deforested India 73,000 years ago – ScienceDaily, 23 November 2009
…. both of the above being essentially regurgitations of this University of Illinois press release.

The Volcanism Blog

%d bloggers like this: