Events & Courses

The present-day differences in the expression and intensity of volcanism on the planets of the inner solar system serves a testament to the dynamic nature of planetary formation and evolution. For example, Earth and Venus are colloquially referred to as sister planets because of their similar size and composition. However, their contrasting volcanology, atmospheric mass and chemistry, climate, and geomorphology are striking.

In short, the Venusian atmosphere and surface contains five orders of magnitude less water than Earth and the average surface temperature on Venus is 460 °C. In addition, Venus is a relatively flat planet, where only 2% of the surface is shows any appreciable topography. Earth, by contrast, has a wet and cold surface with a bimodal topography (e.g. orogenic belts and ocean basins). Suffice to say, these are not identical siblings.

Here I will show how we can combine data from rock-deformation experiments with the chemistry of the Venusian and Terrestrial atmospheres to explain the flatness and relative volcanic quiescence of Venus. In short, I will outline why Earth developed into the crucible of life, and Venus into a hostile wasteland.

Speaker 

Sami Mikhail (University of St Andrew's)

Dr. Mikhail is a lecturer in Earth Sciences at the University of St Andrews (since May 2015), after spending two years as a Carnegie Postdoctoral Fellow at the Geophysical Laboratory (Washington DC, USA) and a couple of postdoctoral positions at the Universities of Bristol and Edinburgh (UK).

Prior to this Dr. Mikhail gained an BSc in Geology from Kingston University (2006), an MSc in Isotope Geochemistry from Royal Holloway and Bedford New College (2007) and a PhD on the origin of diamond-forming carbon at University College London (2011).

The motivation behind Dr. Mikhail’s research is to understand how the interior of a planet affects and controls the composition of its surface and to long-term habitability. Dr. Mikhail’s approach combines investigations of natural samples with high-pressure and -temperature experiments and theoretical models.

Dr. Mikhail has worked on diverse projects such as the source of Icelandic volcanism, diamond-formation in the deep Earth, and more recently, on linking mantle processes to atmospheric chemistry on Earth, Mars, and Venus.