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Cardiff Mantle Plume Conference
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:
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
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."