Did volcanic activity play a role in early human evolution and migration?

October 19, 2016 by David Pyle, Oxford Science Blog, University of Oxford
The Ethiopian Rift Valley suffered colossal volcanic eruptions between about 320,000 and 170,000 years ago. Credit: David Pyle

The great Rift Valley that runs through Ethiopia has played a pivotal role in human evolution. It is both the location of the earliest fossils of anatomically modern humans and, later, become an important route for human migrations 'out of Africa'.

Today, it is home to more than ten million people, a major hub for tourists, and the location of important transport links. The main Ethiopian Rift Valley is also one of the largest fields of volcanoes on Earth – although this status may not be obvious from the remnants of the sprawling tumbledown hills that break through the dusty flats of the rift valley floor. Here, Africa has been slowly pulling apart for millions of years. As the continent pulls apart, the crust extends and thins, promoting the rise of magma from the depths of the Earth's mantle. None of these volcanoes is thought to have erupted since the early 19th century, and several are now the focus of development of geothermal energy potential.

In a new paper published in the journal Nature Communications, Will Hutchison, an Oxford DPhil student, and a team of collaborators from the UK, Ethiopia and the USA, shed a little more light on the violently explosive past of several of these rift volcanoes. Using a combination of field work (to reconstruct the deep history of the volcanoes) and isotopic age dating techniques, the researchers find that at least four of the volcanoes of the main Ethiopian Rift Valley suffered colossal eruptions between about 320,000 and 170,000 years ago. These were very significant eruptions – perhaps of the scale of the eruption of Krakatoa in Indonesia in 1883. They would have buried the rift floor in volcanic ejecta, disrupting water sources and habitats across wide areas, with the collapsed remnants of the volcanic edifices forming great 'calderas', or craters, in the rift floor.

This pulse in volcanism coincides with the arrival of Homo sapiens in the region around 200,000 years ago and raises the question of to what extent these changes in the landscape and environments occupied by our earliest human ancestors might have influenced and migration. The recognition that explosive volcanism in the rift occurs in bursts also poses some interesting geological questions, and future inter-disciplinary research is needed to understand the scale of eruptions at other large volcanoes of the rift, their causes, and their wider consequences.

Explore further: Volcano team get measure of threat to Great Rift Valley

More information: William Hutchison et al. A pulse of mid-Pleistocene rift volcanism in Ethiopia at the dawn of modern humans, Nature Communications (2016). DOI: 10.1038/ncomms13192

Related Stories

Volcano team get measure of threat to Great Rift Valley

August 7, 2014

Little known volcanoes in one of Africa's most stunning locations are to be explored in a bid to understand the threat they pose to life, livelihood and the landscape. Researchers are to assess largely uncharted volcanoes ...

Mosquito-borne Rift Valley fever virus causes miscarriage

October 3, 2016

The mosquito-borne Rift Valley fever virus has been linked to miscarriage in humans. A study of 130 pregnant Sudanese women with fever showed that the risk of miscarriage was seven times greater if the woman was infected ...

Off-rift volcanoes explained

March 23, 2014

Volcanoes often develop outside the rift zone in an apparently unexpected location offset by tens of kilometers has remained unanswered. An international team of scientists has shown that the pattern of stresses in the crust ...

Volcanic plumbing exposed

March 30, 2012

Two new studies into the "plumbing systems" that lie under volcanoes could bring scientists closer to predicting large eruptions.

Magma movements foretell future eruptions

October 7, 2016

Geologists at Uppsala University have traced magma movement beneath Mt. Cameroon volcano, which will help monitoring for future volcanic eruptions. The results are published in Scientific Reports.

Recommended for you

Climate change could increase arable land

May 24, 2018

Climate change could expand the agricultural feasibility of the global boreal region by 44 per cent by the end of the century, according to new research.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.