Geology Bites: An Earth and Planetary Science Podcast

Carolina Lithgow-Bertelloni views plate tectonics and the Earth's topography as an expression of the interior processes of the Earth, and in particular of the horizontal and vertical motions of the mantle.   Here she explains why we think that up to a full kilometer of the Earth's topography is caused by the mantle's direct push or pull on the lithosphere.

Carolina Lithgow-Bertelloni is a Professor of Geosciences at the University of California, Los Angeles.  

Go to geologybites.com to see podcast illustrations and to learn about other Geology Bites episodes. 

Cathy Constable reconstructs global maps of the Earth’s magnetic field over timescales from millennia to millions of years using the remnant magnetism “frozen” into human artifacts and rocks.  This has revealed surprising patterns of variation that in turn cast light on the processes in the Earth’s core that are responsible for generating the field.

Cathy Constable is a Professor at the Scripps Institution of Oceanography. 

Go to geologybites.com to see an animation of the global magnetic field patterns around the time of the last major excursion about 40,000 years ago when the Earth's magnetic field almost vanished entirely. 

Bärbel Hönisch uses the skeletal remains of foraminifera as her raw material in reconstructing ocean and atmospheric conditions that prevailed in past geological periods.  Trace chemical constituents in these creatures can record the temperature of the ocean and carbon dioxide of the atmosphere.  Climate models being applied to the present day are being validated by what she is discovering about the planet’s past evolution.

Go to geologybites.com for illustrations relating to this podcast and to learn more about Geology Bites.

David Rothery investigates volcanism on Earth and elsewhere in the Solar System using remote-sensing Earth-orbiting satellites and space probes.  Mercury is his present focus, and he is lead co-investigator for geology on the X-ray spectrometer aboard BepiColombo, an ESA mission currently on its way to Mercury.  He describes some intriguing puzzles about Mercury that he hopes BepiColombo will resolve, as well as a type of volcanism occurring on some icy bodies in the outer solar system called cryovolcanism.

Go to geologybites.com for illustrations supporting this podcast and to learn more about Geology Bites. 

There are some things we just cannot learn about other bodies in the solar system without actually having our hands on a sample of the body and analyzing it on Earth using the battery of techniques that have been refined for the analysis of terrestrial rocks.  Harold C. Connolly Jr. is Professor and Founding Chair at the Department of Geology at Rowan University.  He investigates the origin of the very oldest planetary materials from which the Earth was made.  Asteroids are a good place to look for such materials, and, to that end, he is Mission Sample Scientist for OSIRIS-REx, a NASA asteroid sample return mission, as well as a member of the Japanese asteroid sample return mission called Hayabusa 2.  He explains how the sample was captured, and what we hope to learn from analyzing it back on Earth.

Go to geologybites.com for illustrations relating to the podcast and to learn more about Geology Bites.

Laurent Jolivet is an expert on the dynamics of tectonic plates and the mantle and is a Professor at the Institute of Earth Sciences at the Sorbonne University.  He combines satellite measurements, seismic tomography, field observations, and computer modeling to reconstruct plate motions, even in some of the most complicated parts of the world.  Here he unravels the tangled evolution of the Mediterranean.

Visit geologybites.com to see maps and animations of the Mediterranean's geological history and of the processes discussed in the podcast. 

Sir Mark Moody-Stuart is a former chairman of Royal Dutch Shell and is a director of Saudi Aramco, which has the largest daily oil production of any oil-producing company. 

He obtained a PhD on the Devonian sediments of Spitsbergen before joining Shell, where he started his career as a geologist in Spain, Oman, Brunei, and Australia.

After recognizing that our response to global warming demands a transformation of our energy strategy, he became a prominent voice for change in the oil industry.   Here, he discusses how he sees this change coming about. 

Go to geologybites.com for illustrations that support this podcast, as well as to learn about other Geology Bites episodes.

The Earth has endured many mass extinctions.  We are pretty confident that we know what caused these events.  Except for one of them: the one at the end of the Devonian period 360 million years ago.  John Marshall is a fossil expert specializing in mass extinction events and is a Professor at the School of Ocean & Earth Science at the University of Southampton.  He explains how his recent research has uncovered new evidence that may finally explain what caused the end-Devonian mass extinction.

Go to geologybites.com for illustrations that support this podcast and to learn more about the series.

So much of what we make starts with materials we extract from the Earth.   Some of these materials make up only a tiny proportion of our planet, but fortunately for us, they are concentrated in certain places, which makes it possible to extract them in economically viable quantities.   So how exactly do these materials become concentrated?

Lawrence Robb is a Visiting Professor at the Department of Earth Sciences at Oxford University.   By analyzing the relationship between mineral deposits, principally in Africa and Asia, and our latest understanding of plate tectonics and mountain-building, he has unraveled the processes that formed some of our most important mineral deposits.

Go to geologybites.com for illustrations that support this episode as well as to learn more about the podcast series.

Bruce Buffett is a Professor in the Department of Earth and Planetary Science at the University of California, Berkeley.   He investigates the structure and motions within the Earth’s core by matching physics-based simulations of the core to the observed magnetic field of the Earth.

Go to geologybites.com for diagrams that support this podcast episode as well as more about the Geology Bites podcast series.