- monatlichErscheinungsrhythmus
- 33 mintypische Länge
- 15. Okt.letzte Folge
Folgenzu den neuesten
Martin Gibling on Rivers in the Geological Record - Part 2
This episode is the second of two of my conversation with Martin Gibling. In the first episode, we discuss fluvial deposits in the geological record and we trace the effect that the break-up of Pangea around 200 million years ago had on riv
Martin Gibling on Rivers in the Geological Record - Part 1
Rivers can seem very ephemeral, often changing course or drying up entirely. Yet some rivers have persisted for tens or even hundreds of millions of years, even testifying to the breakup of Pangea, the most recent supercontinent, about 200
Anna Fleming on the Experience of Rock Climbing
This episode is a bit of a departure from the objective approach to geology of past episodes in that here we address the subjective nature of various rocks as experienced by a rock climber with a literary bent. A rock climber’s very surviva
Brian Upton on the Unique Rift Zone of South Greenland
Between 1.3 and 1.1 billion years ago, magma from the Earth's mantle intruded into a continent during the assembly of the supercontinent called Nuna. Through good fortune, the dykes and central complexes that resulted have been preserved in
Geoff Abers on Subduction Zones and the Geological Water Cycle
Subduction zones are places where a slab of oceanic lithosphere plunges into the mantle below. The slab consists of the sediments on top, crustal rocks in the middle, and the lithospheric mantle on the bottom, all plunging down together as
Maria McNamara on Seeing the Ancient World in Color
Popular reconstructions of ancient environments, whether they be in natural history museum dioramas, in movies, or in books, present a world of color. But are those colors just fanciful renderings, perhaps based on the colors we see around
Phil Renforth on Carbon Sequestration
For many years, efforts to limit climate change have focused on curtailing anthropogenic emissions of greenhouse gases. But it is increasingly clear that such curtailment will not, on its own, be able to prevent the damaging effects of glob
Tony Watts on Seamounts and the Strength of the Lithosphere
When plate tectonics was adopted in the 1960s and early '70s, researchers quickly mapped out plate movements. It seemed that plates moved as rigid caps about a pole on the Earth's surface. But since then, a lot of evidence has accumulated s
Neil Davies on the Greening of the Continents
Life only emerged from water in the Ordovician. By that time, life had been thriving in oceans and lakes for billions of years. What did the colonization of the land look like, and how did it reshape the Earth’s surface? Neil Davies describ
Ben Weiss on the Mission to Psyche
The asteroid Psyche is probably the most metal-rich body we have discovered. There are two, quite different, theories as to how it may have formed: Either it formed that way, or it originally had a more typical composition, but its rocky ou
Roger Bilham on Himalayan Earthquakes
We hear about earthquakes in the Himalaya, especially when they claim lives and cause damage. And we understand that, broadly speaking, it is the continued northward movement of India ploughing into Tibet that causes these earthquakes. But
Susannah Porter on Tiny Vampires in Ancient Seas
The fossil record of complex life goes back far beyond the Cambrian explosion, to as far back as 1,600 million years ago in the late Paleoproterozoic with the first appearance of eukaryotes. But these creatures only started to diversify muc
Ana Ferreira on Seeing Flows in the Mantle
Does the pull of a subducting slab drive plate motions? Or is it the upwellings of convection cells in the mantle? We now have a new way to shed light on this question. It's called seismic anisotropy, which is the spreading out of seismic w
Phil Gibbard on the Anthropocene
There’s a lot of debate about the idea that the global changes brought about by humans define a new geological epoch, dubbed the Anthropocene. Should such an epoch be added to the official geological time scale? If so, what aspect or aspect
David Bercovici on How Plate Subduction Starts
Subduction zones are a fundamental aspect of plate tectonics, yet we still don't really understand how subduction initiates. It's a tough problem because as oceanic plates move away from a mid-ocean spreading center and cool, they get stiff
Bob Hazen on the Evolution of Minerals
New rock types emerge during the history of the Earth. For example, the silica-rich felsic rocks such as granite that characterize continental crust, accumulated during the course of Earth history. Granite only forms in certain specific tec
Matt Jackson on the Heterogeneity of the Mantle
Matt Jackson is a Professor of Earth Science at the University of California, Santa Barbara. He probes the chemical composition of the mantle by analyzing trace elements and isotopes in hot-spot lavas from around the world. In the podcast,
Carmie Garzione on Reconstructing Land Elevation Over Geological Time
Throughout geological history, various points on the Earth’s surface have been lifted up to great elevations and worn down into low, flat-lying regions. Determining surface elevation histories is difficult because rocks that were once on th
Chuck DeMets on High-Resolution Plate Motions
The magnetic stripes frozen into the sea floor as it forms at mid-ocean ridges record the Earth’s magnetic field at the time of formation. Reversals in the Earth’s magnetic field define the edges of these stripes, in effect time-stamping th
Mike Searle on Ophiolite
As the name implies, oceanic lithosphere underlies the oceans of the world. Except when they are ophiolites, when oceanic lithosphere is thrust on top of a continental margin. Are ophiolites a special kind of oceanic lithosphere? Or are the
Mackenzie Day on Dunes
Some of the most extensive sandstone deposits in the world were deposited by wind. How do such aeolian rocks differ from water or ice-deposited rocks? And what do they reveal about the environments in which they formed? In the podcast she d
Sue Smrekar on the VERITAS Mission to Venus
The best maps we have of Venus were made by Magellan, a space probe that flew in the 1990s. In the summer of 2021, NASA approved a new mapping mission that will produce radically improved maps of the topography, radar reflectivity, and grav
Rick Carlson on Probing the Early Solar System
Almost all the evidence about the nascent solar system has been erased by processes accompanying the formation of the Sun and the bodies that formed out of the circumsolar disk about 4.6 billion years ago. But some meteorites and the tiny d
Ed Marshall on Iceland's 2021 Eruption
After months of high earthquake activity, a fissure opened up near the southwestern tip of Iceland on March 19, 2021. Over a period of about seven months, several other fissures opened up, generating lava flows several kilometers long that
Richard Fortey on the Trilobite Chronometer
Long before radiometric dating appeared on the scene, the geological time scale was defined by the sedimentary record, and particularly by key fossils preserved within them. Throughout the Cambrian, and to a lesser extent until the end-Perm
Paul Hoffman on the Snowball Earth Hypothesis
We’re all familiar with the idea of ice ages during which the polar ice caps advance to cover significant portions of their respective hemispheres, and then, after a period of tens to hundreds of thousands of years, retreat back to the pola
Peter Cawood on When Plate Tectonics Started
The heat liberated during the formation of our planet created an ocean of magma. As it began to cool, the Earth differentiated into a dense metallic core surrounded by a less dense rocky mantle. At some point, we know that the surface of th
Becky Flowers on Deciphering the Thermal History of Rocks
Many processes in geology affect the temperature of rocks. Erosion is one example — as a surface is eroded, the rocks below get closer to the surface, cooling as they go. So if we know the temperature history of a rock, we can infer its ero
Ulf Linnemann on the Assembly of Central Europe in the Paleozoic
The geological history of Central Europe is quite complicated. The region is composed of several continental blocks having quite distinct origins that came together over 300 million years ago in the Paleozoic Era. Then, in the Mesozoic, man
Douwe van Hinsbergen on What Drives the Motions of Tectonic Plates
Ever since Alfred Wegener proposed the theory of continental drift in 1912, we have been aware that blocks of the Earth’s lithosphere are moving with respect to each other. With the advent of plate tectonics in the 1960s, these moving block
