🧪⚒️Just released an episode on the dynamics of subduction zones with Claudio Faccenna. Not only do trenches roll back and move laterally, they also advance and flip polarity. But when they penetrate the viscous lower mantle they get locked in place. Enjoy listening!

🧪⚒️I just released Cees Van Staal on the Origin of the Appalachians. The story is closely tied to the Caledonian orogeny across the Atlantic. But today's topography stems from the rifting and magmatism of the much later opening of the Atlantic and the recent ice ages ending 10,000 years ago.

🧪⚒️Just released Andreas Fichtner on the frontiers of seismic imaging. Our images are becoming much sharper— see the episode web page. Really novel is the use of fiber-optic cables to sense seismic waves with unprecedented resolution.

🧪⚒️ Just reposting an invitation to listen to the latest Geology Bites episode on the origin of continents. Adding the 🧪⚒️ icons this time. Renée Tamblyn raises fascinating questions about the Archean water cycle and the role of molecular H in powering the first life forms - the archaea.

When the Earth formed, it was covered by a hot magma ocean. So when and how did thick, silica-rich continental lithosphere form? In the podcast, Renée Tamblyn addresses these questions, as well as how Archaean processes created molecular hydrogen that may have powered the first forms of life.

🧪⚒️Just posted Folarin Kolawole @lamont.columbia.edu on continental rifting. I've always thought that the rifting of continents is a really counterintuitive notion. After teasing out the various early stages with Kolawole and invoking plumes and far-field forces the process makes more sense to me.

🧪⚒️Just released Mike Hudec on salt tectonics. Amazingly, salt structures can be many tens of kilometers across. And because salt is extremely weak compared to other rocks and minerals, it is the first to deform in the presence of stresses. It's often involved in forming hydrocarbon reserves.

🧪⚒️Just back from the European Geophyiscal Union conference. The medalist lectures were great and I signed up two medal winners for Geology Bites. One exciting strand was on the planned probes to the icy moons of Jupiter & Saturn. We’ll be melting our way down through km of ice to reach water!

🧪⚒️I just posted an episode on megafloods with Vic Baker, a pioneer in the field. Megafloods are cataclysmic events that devastate the landscape. The Mediterranean Basin was filled by two successive megafloods. And a Black Sea megaflood might be the basis for the Biblical account of Noah's flood.

🧪⚒️New episode - Lindy Elkins-Tanton on the origin of Earth's water. Only about 0.02% of the Earth is water, but even that's been a puzzle as Earth formed within the snow line where no liquid water would have been present. Isotopic analysis provides the clues to resolve this apparent paradox.

🧪⚒️In this episode, Joeri Witteveen says there is something paradoxical about selecting a single point on Earth to define a global boundary. We also place spikes where the depositional record is continuous. But that is also a bit paradoxical, as such places do not look like boundaries at all.

🧪⚒️I just posted an episode about using the late Paleozoic ice age as an analog to climate conditions today. It was similar in that there was low but rising CO2 and continental ice sheets. Her models suggest possible major ocean anoxia and dramatically increased runoff as CO2 climbs.

I just learned that Richard Fortey passed away yesterday. I loved his books, especially Life and Trilobite. It was so lucky that I managed to get him onto Geology Bites for the second time, this time talking about Deep Time. He was his usual eloquent self, full of insights.

I devoured Richard Fortey's books as a teenager. His magnum opus, Life, was one of my gateways into science. Then when I was writing my first pop science book, Richard generously blurbed it. Getting his testamonial was one of the proudest moments of my life. RIP to a great scientist & writer.

🧪⚒️ Just posted Ruth Siddall @pavementgeology.bsky.social on #urbangeology. You can see so much geology on display in the building stone of almost any city, and often more clearly and certainly more conveniently than going to the field. She guides us through her favorite London urban geology walk.

🧪⚒️ On to the 2nd century of podcasts with Richard Fortey on deep time. Fossils in the geological record were our first markers along the runway of deep time, providing the structure and language within which our modern conception of deep time emerged. #science #geosciences #geology+rocks+Fossils

🧪Geology Bites now has 100 episodes! I hope it will be enough to carry you through any quiet moments during the holidays. Do give me feedback and suggestions and spread the word. #geology #earthscience

🧪 I just posted Mike Searle on the massive mountain ranges of central Asia — the Karakoram, Hindu Kush, Pamir, and 3 others. Each has its own tectonic history and unique features. E.g., an ultra-deep seismic zone in the Hindu Kush and a 700-km-long granite batholith in the Karakoram. #geology

I just posted an episode on the Caledonian orogeny with Rob Strachan. Rob explains this multi-phase three-way continental collision clearly and with a perspective that comes from over 40 years of study on the topic. Having the episode web page handy may be especially helpful for this one.

Listen to a new episode with @joemacgregor.bsky.social on mapping Greenland's geology below the ice. An impressive story of synthesizing decades of geophysical seismic, gravity, and magnetic surveys together with radar and laser altimetry. Newly discovered: long valley networks, 3 new provinces.

There are now 97 episodes of Geology Bites to listen to. They range from deep below us (Evan Smith on diamonds from the mantle) to light-years above us (Sara Seager on exoplanet geology). Do listen and give me feedback, and if you like it, spread the word.

Listen to the new episode with Susan Brantley of @penn_state on Earth's geological thermostat. Overall, her results suggest a doubling of the weathering rate for each 10-degree rise in temperature, but this changes with the spatial scale of the analysis. #earth-science, #geoscience

@earth-science.bsky.social Would you please add me to your list? I am new to Bluesky. I present the Geology Bites podcast geologybites.com. I would like to be able to post to the geology feed. Thanks.

Geology Bites is a podcast for the scientifically curious. In each of the 81 episodes to date, I talk with a leading Earth or Planetary science researcher. Take a look at geologybites.com and see if you like listening either there, or on any of the main podcast apps.