The legendary pugilist Muhammed Ali said ‘The man who views the world at fifty the same as he did at twenty has wasted thirty years of his life’. Our scientific understanding of the Earth shows no such failing, amply demonstrated by the recent “New Views of the Earth’s Interior” meeting held in the Geological Society in London in February. This event, jointly supported by the British Geophysical Association and the Mineralogical Society of Great Britain and Ireland, certainly justified the plural in the title bringing together eminent geochemists, mineral physicists, geodynamicists and seismologists from around the world to discuss recent developments in the study of our planet and beyond. Themes of discussion covered a broad swath of the Earth’s interior, from the crust to the remotest inner core, and out into space.
Perspectives were provided from theoretical, experimental and observational viewpoints. Observations are provided by geochemistry and seismology: the images provided by the latter methods have recently been vastly enhanced by the availability of dense array data.
Presenters showed new, high-resolution images of continental lithosphere, subducting slabs, the transition zone, the enigmatic lowermost mantle region and the solid iron inner core. Seismology, however, detects primarily the velocity of the media it images. To convert this into an understanding of building blocks of the Earth requires input from mineral physics, to describe the nature and behaviour of materials at interior conditions. For example, computational `ab initio’ methods directly model the quantum mechanical behaviour of materials at the atomic level: these are being used to explore the crystal structure which is present in the inner core, and the possibility of melt in the deep mantle. To study real samples experimentalists must reproduce the vast pressures and temperatures in the planet’s interior: in large presses for the transition zone and using diamond anvil cells to simulate the deep core. Results from such experiments exploring the nature of mineral phase changes at the top and bottom of the mantle were presented, as were new insights into the chemistry of the core. Finally, the understanding provided by experiments and computation are being combined in complex simulations of the thermal and chemical dynamics of the whole Earth: such predictions can be compared with the observations of seismology and geochemistry.
The presentations and surrounding discussions underlined a central theme: that the progress we have made and still desire to make requires collaborative effort across a number of disciplines, and such activities are only increasing in scope. This ensures that our views of the Earth’s Interior will continue to evolve and allow synonymous conferences in the future.
The BGA Bullerwell Lecture was delivered by Prof. Sebastian Rost of Leeds University.
- Wookey, on behalf of the Organizing Committee
The following are pdf versions of the powerpoint presentations delivered during the conference. Only those for which permission has been granted are reproduced here.
Effect of phase transformations on seismic velocities
How well can we constrain global radial anisotropy in the Earth’s upper mantle and transition zone?
A new understanding of fluid-rock deformation in crust and upper mantle (5 Mb)
Depleted domains in the convecting upper mantle – constraints from Os isotopes (12.5 Mb)
Grain-boundary sliding and the development of anisotropy (3.5 Mb)
Complex reflectivity of P-wave and S-wave structure in the D” Region (14.5 Mb)
The thickness of the post-perovskite boundary (1.5 Mb)
Thermodynamics of silicate liquids in the deep Earth (4 Mb)
Sebastian Rost, William Bullerwell annual lecture of the British Geophysical Association
Seismic constraints on Earth’s small-scale structure (40 Mb)
Chemical Reactions at the core-mantle boundary (13 Mb)
Structure of the Earth’s core
The effect of light elements on iron stability in the inner core (2.5 Mb)
The origin of the Moon, core formation, and the loss of Earth’s volatiles
Phase relations of Fe-Si-Ni alloys at core conditions: Implications for the Earth’s inner core
- Huw Davies
Is the interior of Venus drier than Earth because of a Mega-collision?
Dynamical origin and consequences of chemical heterogeneity in Earth’s mantle
John Brodholt, convenor Sheila Peacock, Secretary, BGA