IGA NEW YEARLECTURE Wednesday, 23rd January, 2012
Explosive Volcanism and the Eruption of Diamonds
Speaker: Dr Thomas Gernon (University of Southampton)
VENUE: J.M. Synge Lecture Theatre, Arts Building, Trinity College, Dublin 2.
TCD MAP and DIRECTIONS
TIME: 7.00pm
Explosive volcanic eruptions have potential to cause widespread devastation, yet they play a key role in shaping our planet, providing vital mineral resources and governing Earth's climate system. The 2010 eruption of Eyjafjallajökull, Iceland demonstrates how vulnerable we are to the smallest of eruptions, and highlights the importance of the science of volcanology to the global community. In this lecture, we will first visit the Las Cañadas volcanic caldera in Tenerife, Canary Islands (above), which generated at least eight major eruptions during the last 700,000 years. These catastrophic events resulted in eruption columns of over 25 km high and expelled widespread pyroclastic material over 130 km2. By comparison, even the smallest of these eruptions expelled over 25 times more material than that of Eyjafjallajökull. The analysis of crystal nodules from Las Cañadas documents the final processes and changes occurring in the magma plumbing system right through to the moment the volcano erupted — those triggering the catastrophic eruptions. This style of volcanic activity contrasts with other, silica-poor magmas such as kimberlites — volatile-rich magmas from the deep mantle (>150 km), and the primary source of diamonds on Earth. We will visit the planet's hottest and coldest places – the Kalahari Desert, Africa, and NWT Arctic Canada, to provide an insight into the nature of these violent eruptions. In doing so, we will describe a previously unrecognised volcanic process, similar to one used in chocolate manufacturing, which gives important new insights into the dynamics of Diamondiferous magma ascent and eruption.