
Don't Panic Geocast
It's not an exact science.
John Leeman and Shannon Dulin
Show overview
Don't Panic Geocast has been publishing since 2015, and across the 11 years since has built a catalogue of 429 episodes. That works out to roughly 370 hours of audio in total. Releases follow a fortnightly cadence.
Episodes typically run thirty-five to sixty minutes — most land between 44 min and 59 min — and the run-time is fairly consistent across the catalogue. It is catalogued as a EN-language Science show.
The show is actively publishing — the most recent episode landed 2 months ago, with 5 episodes already out so far this year. The busiest year was 2016, with 54 episodes published. Published by John Leeman and Shannon Dulin.
From the publisher
John Leeman and Shannon Dulin discuss geoscience and technology weekly for your enjoyment! Features include guests, fun paper Friday selections, product reviews, and banter about recent developments. Shannon is a field geologist who tolerates technology and John is a self-proclaimed nerd that tolerates geologists.
Latest Episodes
View all 429 episodes
Episode 427 - "Feeding Tubes Yo!"
This week we help a listener identify their bizarre fossil - and it's a trace fossil! Learn all about it and find out if you'd remember more if we were funnier! Trace Fossil Dictionary Shannon’s Favorite Trackway Asterosoma Fun Paper Friday Would you remember more about science if your teachers presented it in a funny way? Frank, Alexandra L., et al. "Wit meets wisdom: the relationship between satire and anthropomorphic humor on scientists' likability and legitimacy." Journal of Science Communication 24.1 (2025): A04.

Episode 426 - "Hard K Sound is Hilarious"
This week, we continue to talk about temperature with a discussion of temperature scales, where they came from, and why there are so many! Fun Paper Friday Kaiser, Caspar, and Andrew J. Oswald. "The scientific value of numerical measures of human feelings." Proceedings of the National Academy of Sciences 119.42 (2022): e2210412119. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 425 - "How jiggly are your bits?"
What is temperature? Why do we care? Where did all of these temperature scales come from? This week, we find out! Fun Paper Friday Di Lorenzo, Emilia, et al. "Periodic cooking of eggs." Communications Engineering 4.1 (2025): 1-10. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 424 - "Aunt Betty" Liquefaction
This week it's all about liquefaction as we explore why some caskets are above ground and how some cars get half way buried. Flame Structure Sand Boil Quicksand Fun Paper Friday Can creatively shaped pasta fold itself when cooked? Tao, Ye, et al. "Morphing pasta and beyond." Science Advances 7.19 (2021): eabf4098. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 423 - "The rumors of our death"
We are back after a very challenging 2025 but don't panic - there is a plan! Fun Paper Friday Taloni, Andrea, Vincenzo Scorcia, and Giuseppe Giannaccare. "Large language model advanced data analysis abuse to create a fake data set in medical research." JAMA ophthalmology 141.12 (2023): 1174-1175. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 422 - "Melissa"
We're still here - it has just been a very difficult time, but this week we're talking about Hurricane Melissa and Halloween Candy! Hurricane Melissa Video Inside the Hurricane Fun Paper Friday Trick or Treat! Maybe it should be Treat or Toy? Find out in this week's Fun Paper! Schwartz, Marlene B., Eunice Y. Chen, and Kelly D. Brownell. "Trick, treat, or toy: children are just as likely to choose toys as candy on Halloween." Journal of nutrition education and behavior 35.4 (2003): 207-209. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 421 - "Come work for you"
This week, we chat about our GEARS workshop that recently wrapped up, how it has evolved, and how it went! GEARS Workshop Fun Paper Friday Hejnol, Andreas, and Mark Q. Martindale. "The mouth, the anus, and the blastopore—open questions about questionable openings." Animal Evolution: Genomes, Fossils, and Trees (2009): 33-40. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 420 - "Tourist Destination" Kamchatka Earthquake
This week we are back and discussing the recent large earthquake in Russia! Fun Paper Friday Is that viral video of a fault rupture form a security camera real? This paper checks it out. Kearse, Jesse, and Yoshihiro Kaneko. "Curved Fault Slip Captured by CCTV Video During the 2025 M w 7.7 Myanmar Earthquake." The Seismic Record 5.3 (2025): 281-288. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 419 - "Diamonds Everywhere" A States
We're hitting the open road — geologically speaking. This episode kicks off our new state-by-state series covering the most fascinating, scenic, or just plain weird geologic stops in the U.S. We’re going alphabetically (because of course we are), starting with Alabama, Alaska, and Arkansas. Some sites we've visited, others are firmly on our dream list, but every pick is guaranteed to bring a bit of science to your next adventure. Alabama Cheaha Mountain Cathedral Caverns Alaska Wrangell-St. Elias National Park Mendenhall Glacier Arkansas Crater of Diamonds State Park Blanchard Springs Caverns Fun Paper Friday Frost, Mungo, et al. "Diamond precipitation dynamics from hydrocarbons at icy planet interior conditions." Nature astronomy 8.2 (2024): 174-181. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 418 - "I like the crystal habit"
What makes a mineral a favorite? In this fun and down-to-earth episode, John and Shannon swap stories about the minerals they love most — and why. Along the way, they unpack cool crystal habits, formation environments, fieldwork memories, and the aesthetic appeal of minerals from museum specimens to muddy boots. Shannon shares her appreciation for: Hematite – With its metallic luster and planetary significance. Goethite – A subtle but important iron oxide-hydroxide. Smithsonite – Beautiful colors and a fascinating history in ore geology. John counters with: Ulexite – “TV rock,” with fiber-optic properties that never fail to wow. Uraninite – A dense, radioactive reminder of geologic power and energy. Tourmaline – A colorful, complex favorite of mineral collectors and scientists alike. Fun Paper Friday James, C. W., et al. "A nanosecond-duration radio pulse originating from the defunct Relay 2 satellite." The Astrophysical Journal Letters 987.1 (2025): L16. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 417 - "Who are you?"
We're back from summer break - Shannon taught field camp, John travelled for work and got hailed on, and more! John’s Hail Storm Fun Paper Friday How does modern AI stack up against a cognition test designed for humans? Dayan, Roy, Benjamin Uliel, and Gal Koplewitz. "Age against the machine—susceptibility of large language models to cognitive impairment: cross sectional analysis." bmj 387 (2024). Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 416 - "Life is a Physics Exam"
This week we talk about how we power our instruments in the field and all of the weird and wonderful ways they fail. Including getting turned into charcoal by lightning! Fun Paper Friday Why does ketchup splatter? Find out! Arstechnica Article Cuttle, Callum, and Christopher W. MacMinn. "Dynamics of compression-driven gas-liquid displacement in a capillary tube." Physical Review Letters 130.11 (2023): 114001. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 415 - "Fiat 500 Volcanic Bomb"
This week we talk hail, Vesuvius, volcanic bombs, and vitrified brains. Scandone, Roberto, Lisetta Giacomelli, and Mauro Rosi. "Death, Survival and Damage during the 79 AD Eruption of Vesuvius which destroyed Pompeii and Herculaneum." J. Res. Didact. Geogr 2 (2019): 5-30. Fun Paper Friday An amazing new finding shows that brains were vitrified or turned to glass during the nearly 2000 year old eruption of Vesuvius. Giordano, Guido, et al. "Unique formation of organic glass from a human brain in the Vesuvius eruption of 79 CE." Scientific Reports 15.1 (2025): 5955. Mt Vesuvius Plinian Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 414 - "Closed Because of Landslide"
Shannon's class took a trip to study catestrophic sedimentation... and they found it! John switched back to a Mac after 5 years. Join us for these and other exciting updates! Fun Paper Friday Find out how alcohol and an eye puffer machine cominbed with magnets can teach us about where our motor skills reside in the brain. Johansson, Fredrik, et al. "Alcohol impairs learning and timing of conditioned eyeblink responses." Brain Research 1854 (2025): 149545. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 413 - "Waterfalls I Have Loved"
Turner Falls, Oklahoma A rare waterfall that grows outward due to travertine deposition instead of eroding backward. Formed by spring-fed Honey Creek flowing through Ordovician limestone, creating massive travertine deposits. Pe'ePe'e Falls, Hawai'i (Big Island) ~80 ft falls in downtown Hilo, part of the Wailuku River flowing between Mauna Kea and Mauna Loa. Carved into 10,000-year-old lava flows with subsequent flows creating the Boiling Pots — vertical and horizontal lava tubes. Extremely dangerous, especially after storms — known as the deadliest water in Hawai'i. Cataratas do Iguaçu, Brazil/Argentina Largest waterfall system in the world, spanning the Argentina-Brazil border. Name means "Big Water" in Guarani. Upstream from the Itaipu Dam, which generates most of Paraguay’s electricity. Itaipu — the 3rd largest hydroelectric plant globally and 2nd in power output. Bonus Waterfalls Mentioned: Cascata delle Marmore, Italy – Ancient Roman-engineered waterfall. Natural Falls - West Siloam Springs, OK Devil’s Kettle, Minnesota – Mysterious waterfall where water seems to disappear underground. Fun Paper Friday What can spacecraft learn from cats? Zhang, Li, et al. "Analysis of Cushioned Landing Strategies of Cats Based on Posture Estimation." Biomimetics 9.11 (2024): 691. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 412 - "Unpopular Flavor of Capri Sun"
This week we talk about snow forecasting as the winter season starts to wrap up and try to figure out if you're really happier in the morning or not! Fun Paper Friday https://mentalhealth.bmj.com/content/28/1/e301418 Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 411 - "TSA Does Not Care About Your Data "
Ever wondered how geologists figure out when a landslide happened? Or how ancient river terraces and glacial deposits get dated? This week, we dive into the detective work behind dating geomorphic features! 🌍🔬 From tree rings to cosmic rays, we explore the fascinating methods geologists use to reconstruct Earth’s history and assess natural hazards. Why Dating Landslides and Other Features is Hard Landslides can reactivate multiple times, fluvial deposits get reworked, and glacial features have complex histories. What are we really dating—the event, the material, or the last exposure? Dating Techniques in Geology Dendrochronology 🌲 – Tree rings reveal landslides, floods, and debris flows. Radiocarbon Dating 💀 – Organic material like charcoal and buried soil horizons provide time markers. Optically Stimulated Luminescence (OSL) 🌞 – Measures when quartz grains were last exposed to sunlight. Cosmogenic Nuclide Dating ☄️ – Tracks surface exposure using cosmic rays. Other Methods – Lichen growth, volcanic ash layers, and earthquake trenching. Fun Paper Friday Ever wondered if your favorite neon-orange snack has hidden superpowers? This study explores how strongly absorbing molecules, like those found in food dyes, can reduce light scattering in biological tissues—making them temporarily more transparent! Researchers applied tartrazine (a common food coloring) to live mice and were able to see internal structures like blood vessels without invasive procedures. The discovery could improve biomedical imaging, but we’re mostly just fascinated that Dorito dust might have unexpected side effects! Ou, Zihao, et al. "Achieving optical transparency in live animals with absorbing molecules." Science 385.6713 (2024): eadm6869. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 410 - "GEARS OIL UTEP"
We just wrapped up our first-ever on-site GEARS Workshop at UTEP and it was a massive success! 🎉 Tune in as we break down the highlights, what we learned, and how this hands-on geoscience training is evolving for the future. Fun Paper Friday Can paranormal lights actually be tied to earthquakes? Hough, Susan E. "Haunted Summerville: Ghostly Lights or Earthquake Lights?." Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 409 - "Resolutions"
This week, it's time for our 2025 resolutions show, where we see how we can improve this year and discuss everything that's changed in the past year! Fun Paper Friday We are all overloaded with surveys and requests, but can a chocolate bar increase the response rates? Jamtvedt, Gro, et al. "Chocolate bar as an incentive did not increase response rate among physiotherapists: a randomised controlled trial." BMC research notes 1 (2008): 1-4. Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin

Episode 408 - "Everywhere there's cottonwood trees"
This week we wrap up our finding faults show started oh so long ago! Learn how to identify faults in the field and then relax with a coffee with a physicist! A perfectly spherical coffee on a frictionless plane that is! Fun Paper Friday Bossart, Aleksi, Romain Fleury, and Benjamin Apffel. "Science of a coffee cup: a physicist walks into a bar..." arXiv preprint arXiv:2501.01180 (2025). Contact us: Show Support us on Patreon! www.dontpanicgeocast.com @dontpanicgeo [email protected] John Leeman www.johnrleeman.com @geo_leeman Shannon Dulin @ShannonDulin