Cardiff Mantle Plume Conference

["Dewey M. McLean" <dmclean@vt.edu>]

Dear Colleagues,

Did anyone on the list attend the Cardiff University September 2003 
conference on mantle plumes and climate changes, extinctions, etc.? A 
short write-up on the conference can be accessed at: 
http://www.spacedaily.com/news/life-03zr.html

Here it is:

Did Earth Blow Up The Dinosaurs

Dino WorldCardiff - Sep 11, 2003

New evidence supports volcanic eruption theory The extinction of the 
dinosaurs - thought to be caused by an asteroid impact some 65 
million years ago - was more likely to have been caused by a 'mantle 
plume' - a huge volcanic eruption from deep within the earth's 
mantle, the region between the crust and the core of the earth.

This theory, already supported by a significant body of geologists 
and palaeontologists, is strengthened by new evidence to be presented 
at an international conference at Cardiff University on 11-12 
September.

Research by an American earth scientist, Professor Gerta Keller and 
her team, suggests that a similar eruption under the Indian Ocean 
several million years before the extinction of the dinosaurs had a 
similarly devastating impact on the environment. However, at this 
earlier time there is no evidence of any asteroid impact.

Her findings are based on analysis of microfossil assemblages, which 
were found inside cores that had been drilled deep into sediments on 
the ocean floor.

The eruptions that were responsible for these two extinction events 
were as a result of mantle plumes - a phenomenon caused by rising hot 
mantle from deep within the earth.

Likened to the actions of a lava lamp, the mantle's heat causes it to 
rise and mushroom out; it then flattens causing the mantle to melt 
and erupt magma over the earth's surface and across an area of some 
1,000 kilometres diameter.

These eruptions last between one and two million years and more than 
one million cubic kilometres of lava can be erupted in that time.

Today, we can witness seven huge remnants of such mantle plume 
activity. These are also known as 'hotspots' and are responsible for 
the volcanic activity on Iceland, the islands of Hawaii, Easter, 
Reunion, Tristan and Louisville as well as volcanism in the Afar 
region of Ethopia.

"Mantle plumes are literally a hot topic for debate," said conference 
organiser Dr Andrew Kerr of Cardiff University's School of Earth, 
Ocean and Planetary Sciences.

"They are a catalyst for the formation of ocean basins and 
fundamentally reshaping the earth's surfaces. The massive outpouring 
of lava, ashes, and gas can have significant effects on climate, 
which destabilises the environment and have the potential to dictate 
the course of evolution. It is likely that were it not for mantle 
plumes, mammals would not have become predominant, and humankind 
would not be here today.

"Bizarrely, amongst earth scientists, there is also a vocal minority 
who don't believe that mantle plumes exist at all. This conference is 
therefore an opportunity to address these issues and validity of the 
links between mantle plumes with the evolution of life by bringing 
together geophysicists, petrologists and palaeontologists."

Cordially,
Dewey McLean