Rob Strachan on the Caledonian Orogeny

Geology Bites

#Science #Geology #Oliver Strimpel

43:56

On August 20th, 1989, Lyle and Erik Menendez shot and killed their own parents. Until then, this Beverly Hills family had been a portrait of the American Dream. How did it go so wrong? To listen to all four episodes of 'The Menendez Brothers' right now and ad-free, go to IntoHistory.com . Subscribers enjoy uninterrupted listening, early releases, bonus content and more, only available at IntoHistory.com . If you or someone you know is in crisis, there is free help available at mhanational.org Learn more about your ad choices. Visit megaphone.fm/adchoices…

год назад 39:26

MP3•Главная эпизода

The Caledonian orogeny is one of the most recent extinct mountain-building events. It took place in several phases during the three-way collision of continental blocks called Laurentia, Baltica, and Avalonia during the early stages of the assembly of the supercontinent Pangea. In the process, Himalayan-scale mountains were formed. While these mountains have been worn down today, we still see plenty of evidence for their existence in locations straddling the Atlantic and the Norwegian Sea. In the podcast, Rob Strachan describes the tectonic movements that led to the orogen and explains how we can reconstruct the sequence of events that occurred and what we can learn about today’s mountain-forming processes by studying the exhumed rocks of ancient orogens.

Strachan has studied the rocks of the Caledonian orogen for over 40 years, focusing on unraveling the history of the orogen in what is Scotland today. He is Emeritus Professor of Geology at the University of Portsmouth.

102 эпизодов

Geology Bites

Rob Strachan on the Caledonian Orogeny

Geology Bites

39 subscribers

published год назад

MP3•Главная эпизода

102 эпизодов

#Science #Geology #Oliver Strimpel

Все серии

Geology Bites

1
Ruth Siddall on Urban Geology 33:53

14 дней назад33:53

33:53

At first sight, urban geology sounds like an oxymoron. How can you do geology with no rocky outcrops anywhere in sight within the built-up environments of cities? It turns out you can do a great deal of geology, and Ruth Siddall has been doing just that for the past 10 years. In the podcast, she describes some of the many aspects of geology, from petrology to paleontology, that can be seen very clearly in building stone. She also takes us on a walking tour in London from the Monument to the Great Fire of London to the Tower of London. Siddall has developed nearly 50 urban geology-themed walks and built up a database of over 4,300 urban localities of geological interest. She is a postdoctoral researcher at Trinity College, Dublin, studying the social history and geological provenance of stone in 18th century buildings in Britain and Ireland.…

Geology Bites

1
Richard Fortey on Deep Time 29:48

8 weeks назад29:48

29:48

The Earth is about 4.5 billion years old. How can we begin to grasp what this vast period of time really means, given that it is so far beyond the time scale of a human life, indeed of human civilization? Richard Fortey has devoted his long and prolific research career at the Natural History Museum in London to the study of fossils, especially the long-extinct marine arthropods called trilobites. In an earlier episode of Geology Bites , he talked about measuring time with trilobites. In this episode, he describes how it was the fossils in the geological record that gave us the first markers along the runway of deep time, providing the structure and language within which our modern conception of deep time emerged.…

Geology Bites

1
Mike Searle on the Mountain Ranges of Central Asia 34:31

11 weeks назад34:31

34:31

The Himalaya are just one, albeit the longest and highest, of several mountain ranges between India and Central Asia. By world standards, these are massive ranges with some of the highest peaks on the planet. The Karakoram boasts four of the world’s fourteen 8,000-meter peaks, and the Hindu Kush, the Pamir, the Kunlun Shan, and the Tien Shan each have many peaks above 7,000 meters. No mountain ranges outside this region have such high mountains. Yet we seldom hear much about these ranges. In the podcast, Mike Searle describes the origin and geology of six central Asian ranges and how they relate to the Himalaya and the collision of India with Asia. India continues to plow into Asia to this day. How is this movement accommodated? Searle explains the extrusion and crustal shortening models that have been proposed and describes the detailed mapping he and his colleagues conducted in the field in northern India that showed that both mechanisms are operating. Searle is Emeritus Professor of Earth Sciences at the University of Oxford.…

Geology Bites

1
Rob Strachan on the Caledonian Orogeny 39:26

12 weeks назад39:26

39:26

Geology Bites

1
Joe MacGregor on Mapping the Geology of Greenland Below the Ice 31:10

16 weeks назад31:10

31:10

With most of Greenland buried by kilometers of ice, obtaining direct information about its geology is challenging. But we can learn a lot from measurements of the island’s geophysical properties — seismic, gravity, magnetic from airborne and satellite surveys and from its topography, which we can see relatively well through the ice using radar. In the podcast, Joe MacGregor explains how he created a new map of Greenland’s geology and speculates on what we can learn from it. MacGregor is a Research Physical Scientist at NASA’s Goddard Space Flight Center.…

Geology Bites

1
Adam Simon on Battery Metals 34:14

19 weeks назад34:14

34:14

As we wean ourselves away from fossil fuels and ramp up our reliance on alternatives, batteries become ever more important for two main reasons. First, we need grid-scale batteries to store excess electricity from time-varying sources such as wind and solar. Second, we use them to power electric vehicles, which we are now producing at the rate of about 15 million a year worldwide. So far, the battery of choice is the lithium-ion battery. In addition to lithium, these rely on four metals — copper, nickel, cobalt, and manganese. In the podcast, Adam Simon explains the role these metals play in a battery. He then describes the geological context and origin of the economically viable deposits from which we extract these metals. Simon is a professor of economic geology at the University of Michigan.…

Geology Bites

1
Rufus Catchings on Pinning Down California's Faults 33:33

24 weeks назад33:33

33:33

Knowing exactly where faults are located is important both for scientific reasons and for assessing how much damage a fault could inflict if it ruptured and caused an earthquake. In the podcast, Rufus Catchings describes how we can use natural and artificial sources of seismic waves to create high-resolution images of fault profiles. He also explains how faults can act as seismic waveguides, an effect that enables us to determine whether faults are connected to each other. In Napa, a famous wine-growing area near San Francisco, he used guided waves to determine that an active fault is actually ten times longer than previously thought. Rufus Catchings is a Research Geophysicist at the US Geological Survey (USGS). Over the past 40 years, he has studied many dozens of faults in California and elsewhere to pin down their precise locations and help assess the risks they pose.…

Geology Bites

1
Sara Seager on Exoplanet Geology 34:33

27 weeks назад34:33

34:33

During the past couple of decades, we have discovered that stars with planetary systems are not rare, exceptional cases, as we once assumed, but actually quite commonplace. However, because exoplanets are like fireflies next to blinding searchlights, they are incredibly difficult to study. Yet, as Sara Seager explains, we are making astonishing progress. Various ingenious methods and the use of powerful space telescopes enable us to learn about exoplanet atmospheres and even, in some cases, what their surfaces consist of. Sara Seager’s research concentrates on the detection and analysis of exoplanet atmospheres, and she has just won the prestigious Kavli Prize for this work. She has had leadership roles in space missions designed to discover new exoplanets and find Earth analogs orbiting a sun-like star. She is a Professor of Aeronautics and Astronautics, Professor of Planetary Science, and Professor of Physics at the Massachusetts Institute of Technology.…

Geology Bites

1
Evan Smith on Diamonds from the Deep Mantle 34:36

29 weeks назад34:36

34:36

We have only a tantalizingly small number of sources of information about the Earth’s deep mantle. One of these comes from the rare diamonds that form at depths of about 650 km and make their way up to the base of the lithosphere, and then later to the surface via rare volcanic eruptions of kimberlite magma. In the podcast, Evan Smith talks about a new class of large gem-quality deep-mantle diamonds that he and his coworkers discovered in 2016. Inclusions within these diamonds serve as messenger capsules from the deep mantle. They show an unmistakable genetic link to subducted oceanic slabs, and thus give us clues as to what happens to subducted slabs as the pass through the lower mantle transition zone. Evan Smith is a Senior Research Scientist at the Gemological Institute of America, New York.…

Geology Bites

1
Roberta Rudnick on the Continental Crustal Composition Paradox 27:53

31 weeks назад27:53

27:53

Continental crust is derived from magmas that come from the mantle. So, naively, one might expect it to mirror the composition of the mantle. But our measurements indicate that it does not. Continental crust contains significantly more silica and less magnesium and iron than the mantle. How can we be sure this discrepancy is real, and what do we think explains it? In the podcast, Roberta Rudnick presents our current thinking about these questions. Surprisingly, more than 30 years after she and others first identified the so-called continental crustal composition paradox, there is still no consensus among geologists as to which of the many proposed hypotheses most convincingly solves the paradox. Rudnick is a Distinguished Professor in the Department of Earth Science at the University of California Santa Barbara.…

Geology Bites

1
Alex Copley on Soft Continents 32:04

33 weeks назад32:04

32:04

We tend to think of continental tectonic plates as rigid caps that float on the asthenospheric mantle, much like oceanic plates. But while some continental regions have the most rigid rocks on the planet, wide swathes of the continents are not rigid at all. In the podcast, Alex Copley explains how this differentiation comes about and points to evidence that the responsible processes have been operating since the Archean. Copley is Professor of Tectonics in the Department of Earth Sciences at the University of Cambridge.…

Geology Bites

1
Shanan Peters on Quantifying the Global Sedimentary Rock Record 27:14

35 weeks назад27:14

27:14

Shanan Peters believes we need to assemble a global record of sedimentary rock coverage over geological time. As he explains in the podcast, such a record enables us to disentangle real changes in the long-term evolution of the Earth-life system from biases introduced by the unevenness and incompleteness of the sedimentary record. To this end, he and his team have established Macrostrat, a platform for the aggregation and distribution of our knowledge about the spatial and temporal distribution of sedimentary rocks. In the podcast, he describes some important findings made possible by Macrostrat. One of them is that gaps in the record are often as revealing about the underlying processes involved as the rocks preserved above and below the gaps. Peters is a Professor in the Department of Geoscience at the University of Wisconsin-Madison.…

Geology Bites

1
Paul Smith on the Cambrian Explosion 32:44

39 weeks назад32:44

32:44

Complex life did not start in the Cambrian - it was there in the Ediacaran, the period that preceded the Cambrian. And the physical and chemical environment that prevailed in the early to middle Cambrian may well have arisen at earlier times in Earth history. So what exactly was the Cambrian explosion? And what made it happen when it did, between 541 and 530 million years ago? Many explanations have been proposed, but, as Paul Smith explains in the podcast, they tend to rely on single lines of evidence, such as geological, geochemical, or biological. He favors explanations that involve interaction and feedback among processes that stem from multiple disciplines. His own research includes extensive study of a site where Cambrian fossils are exceptionally well preserved in the far north of Greenland. Smith is Director of the Oxford University Museum of Natural History and Professor of Natural History at the University of Oxford.…

Geology Bites

1
Scott Bolton on the Most Volcanically Active Body in the Solar System 24:45

41 weeks назад24:45

24:45

Jupiter's innermost Galilean moon, Io, is peppered with volcanos that are erupting almost all the time. In this episode, Scott Bolton, Principal Investigator of NASA's Juno mission to Jupiter, describes what we're learning from this space probe. Since its arrival in 2017, its orbit around the giant planet has progressively shifted to take it close to Jupiter’s moons and rings. In December 2023 and February 2024, it flew by Io, approaching within a distance of only 1,500 km. This enabled Juno to capture high-resolution imagery of its constantly changing surface, including hitherto unseen regions near its poles. As discussed in the podcast, Juno is equipped with a microwave instrument that enables it to look slightly below the moon’s surface into its lava lakes, as well as a suite of magnetometers to study Jupiter’s giant magnetosphere and its remarkable interaction with Io. Bolton’s research focuses on Jupiter and Saturn and the formation and evolution of the solar system. Prior to the Juno mission, he led a number of science investigations on the Cassini, Galileo, Voyager, and Magellan missions. He is Director of the Space Sciences Department at Southwest Research Institute in San Antonio, Texas.…

Geology Bites

1
Bob White on How Magma Moves in the Crust 36:45

43 weeks назад36:45