Podcasts about geodynamo

Dive into the cosmic depths with SpaceTime Series 27 Episode 54, where we journey back 3.7 billion years to uncover the oldest evidence of Earth's magnetic field. Join us as we explore pristine ancient rocks from Greenland, revealing a magnetic strength similar to today's, and potentially extending the known age of our planet's protective shield by hundreds of millions of years. This discovery could illuminate the early conditions that fostered life on Earth and the enduring power source behind our magnetic field.The volcanic spectacle continues as we venture to Jupiter's moon Io, unveiling that it has been a hotbed of volcanic activity for its entire 4.57 billion-year existence. The sulfur and chlorine isotopes in Io's atmosphere, analyzed through the Alma radio telescope, attest to a history of relentless eruptions powered by Jupiter's immense gravitational pull.Witness the marvels of the solar corona as we recap the scientific endeavors during the recent solar eclipse that graced North America. From sounding rockets to high-altitude jets, scientists harnessed this celestial event to probe the enigmatic corona, seeking to solve the mystery of its intense heat and its role in geomagnetic storms that affect our increasingly tech-dependent world.And in a turn towards Earthly concerns, we discuss the unsettling findings that nearly half of China's major coastal cities are sinking, posing a threat to millions.For a comprehensive voyage through these astronomical discoveries and terrestrial challenges, visit https://spacetimewithstuartgary.com and support the show at https://www.spreaker.com/show/spacetime. Immerse yourself in the wonders of the universe with SpaceTime.This episode is proudly supported by NordPass. Safeguard your digital journey across the infinite expanse with a password manager you can count on. Secure your celestial navigation at www.bitesz.com/nordpass.Tune into SpaceTime on your preferred podcast app and follow us on Twitter @stuartgary, Instagram, YouTube, and Facebook.Become a patron for exclusive access to ad-free episodes and special content: https://www.spreaker.com/podcast/spacetime-with-stuart-gary--2458531/support.

Die Erde hat ein Magnetfeld und wir können froh darüber sein. Aber wie schaut es bei den anderen Planeten aus? Wo es da magnetisch ist und wo nicht, erfahrt ihr in der neuen Folge der Sternengeschichten. Wer den Podcast finanziell unterstützen möchte, kann das hier tun: Mit PayPal (https://www.paypal.me/florianfreistetter), Patreon (https://www.patreon.com/sternengeschichten) oder Steady (https://steadyhq.com/sternengeschichten)

Learn about why you can blame redlining for US cities being so segregated; why Earth’s magnetic north pole is drifting every year; and how virtual therapy can be just as effective as in-person therapy. Redlining is the totally legal reason why US cities are so segregated by Steffie Drucker NPR. (2020). Why Cities Are Still So Segregated | Let’s Talk | NPR [YouTube Video]. In YouTube. https://www.youtube.com/watch?v=O5FBJyqfoLM  ‌The Root. (2020). How Redlining Shaped Black America As We Know It | Unpack That [YouTube Video]. In YouTube. https://www.youtube.com/watch?v=2o-yD0wGxAc  New Deal | Definition, Programs, Summary, & Facts | Britannica. (2020). In Encyclopædia Britannica. https://www.britannica.com/event/New-Deal  FDR and Housing Legislation - FDR Presidential Library & Museum. (2012). Fdrlibrary.org. https://www.fdrlibrary.org/housing  National Housing Act Definition | Bankrate.com. (2020, May 12). Bankrate. https://www.bankrate.com/glossary/n/national-housing-act/  Mitchell, B. (2018, March 20). HOLC “redlining” maps: The persistent structure of segregation and economic inequality » NCRC. NCRC. https://ncrc.org/holc/  Alix, L. (2019, December 16). Wells Fargo, Philadelphia reach settlement in redlining lawsuit. American Banker; American Banker. https://www.americanbanker.com/news/wells-fargo-philadelphia-reach-settlement-in-redlining-lawsuit  Perry, A. M., & Harshbarger, D. (2019, October 14). America’s formerly redlined neighborhoods have changed, and so must solutions to rectify them. Brookings; Brookings. https://www.brookings.edu/research/americas-formerly-redlines-areas-changed-so-must-solutions/  Earth's magnetic north pole is drifting every year by Cameron Duke Livermore, P. W., Finlay, C. C., & Bayliff, M. (2020). Recent north magnetic pole acceleration towards Siberia caused by flux lobe elongation. Nature Geoscience, 13(5), 387–391. https://doi.org/10.1038/s41561-020-0570-9 McRae, M. (2020). Earth’s Magnetic North Is Moving From Canada to Russia, And We May Finally Know Why. ScienceAlert. https://www.sciencealert.com/russia-is-stealing-magnetic-north-from-canada-and-this-could-be-what-s-behind-it Mohr, K. (2020). Geodynamo | Earth. NASA.gov. https://earth.gsfc.nasa.gov/geo/research/geodynamo  ‌Glatzmaier, G. (1996). The Geodynamo. UCSC.edu. https://websites.pmc.ucsc.edu/~glatz/geodynamo.html  Toomey, E. (2019, August 7). Earth’s Magnetic Field Could Take Longer to Flip Than Previously Thought. Smithsonian Magazine; Smithsonian Magazine. https://www.smithsonianmag.com/science-nature/earths-magnetic-field-could-take-longer-flip-previously-thought-180972843/  What Will Happen When Earth’s North And South Pole Flip? (2018). [YouTube Video]. https://www.youtube.com/watch?v=I6Ggs7nUjxA Virtual therapy can be just as effective as in-person therapy by Andrea Michelson Effects of internet CBT for health anxiety on par with face-to-face treatment. (2020). EurekAlert! https://www.eurekalert.org/pub_releases/2020-05/ki-eoi051220.php  ‌Axelsson, E., Andersson, E., Ljótsson, B., Björkander, D., Hedman-Lagerlöf, M., & Hedman-Lagerlöf, E. (2020). Effect of Internet vs Face-to-Face Cognitive Behavior Therapy for Health Anxiety. JAMA Psychiatry. https://doi.org/10.1001/jamapsychiatry.2020.0940  What you need to know before choosing online therapy. (2015). American Psychological Association. APA.org. https://www.apa.org/helpcenter/online-therapy  ‌Suzannah Weiss. (2018, June 7). How to Know if You’d Do Better With Online Therapy Versus In-Person. Vice; vice. https://www.vice.com/en_us/article/vbqp48/is-in-person-therapy-better-than-online-therapy  Subscribe to Curiosity Daily to learn something new every day with Cody Gough and Ashley Hamer. You can also listen to our podcast as part of your Alexa Flash Briefing; Amazon smart speakers users, click/tap “enable” here: https://www.amazon.com/Curiosity-com-Curiosity-Daily-from/dp/B07CP17DJY 

Engine efficiency, what happens when the Earth's magnetic field flips, what is a solar minimum, why are some people shorter than others and what causes dwarfism, and how can I tell planets from stars? Join 702's Azania Mosaka and Dr Chris Smith for the answers... Like this podcast? Please help us by supporting the Naked Scientists

Engine efficiency, what happens when the Earth's magnetic field flips, what is a solar minimum, why are some people shorter than others and what causes dwarfism, and how can I tell planets from stars? Join 702's Azania Mosaka and Dr Chris Smith for the answers... Like this podcast? Please help us by supporting the Naked Scientists

Many physical features of Neanderthals might not be for cold climate adaptation as previously thought. They may be for types of locomotion. Which, according to paleo-ecologist, John Stewart at Bournemouth University, makes the long thigh to calf ratios more likely that Neanderthals were adapted to fast, powerful sprints, as part of their hunting and survival. The clues to this lie less in the bones and more in the evidence that Neanderthals lived in wooded areas rather than tundra. Earth’s solid iron inner core, liquid outer core and interactions between the two give us our protective magnetic field and are responsible for the ‘geodynamo’ that drives this, as well as volcanism and Earth’s tectonics. But we don’t yet know when the solid core formed. It’s hard to find paleo-magnetic records from early in Earth’s history. But now a group at Rochester University in New York have discovered magnetic particles from 565 million year old Ediacaran Period rocks in Canada and they say that at the time lots of life was evolving on our planet, the geodynamo was low and wobbly. This leads them to believe the solid core formed two to three times later than previously thought. A typical sneeze will throw out 40,000 tiny droplets loaded with viruses or bacteria, which can hang in the air like a cloud until someone else comes along and inhales some. To a scientist, this suspension is an aerosol, and what goes on inside a tiny droplet can be very different from what happens in a beaker of fluid. But studying those conditions, which can alter whether a germ can survive its aerial journey is hard. Which is why at Bristol University they’ve developed an aerosol trap that can hold droplets mid-air, without contact, with an electric field. Rabbits and hares across Europe have been declining rapidly over the past few decades. There are a number of factors involved (Agricultural intensification, climate change, hunting and a whole host of infectious diseases.) Myxomatosis in rabbits, which has now jumped into hares, is fairly well known by the public, but there are other viral and bacterial diseases that are jumping between the species and the most recent one Rabbit Hemorrhagic Disease Virus 2 (RHDV2) is of particular concern right now. Very little is known about this disease in wild populations. It was seen in hares in Europe a few years back, but it’s now just been identified in the UKs native brown hare population. Biologist Diana Bell at the University of East Anglia wants the public to contact her if they see any hares that look like they’ve died from the disease. Producer - Fiona Roberts

Schwerpunkt: Stuart Gilder von der LMU München erklärt, wie das Magnetfeld der Erde erzeugt wird und wie es sich im Lauf der Zeit verändert || Nachrichtenspezial: Gravitationswellen erstmals direkt gemessen

The Greek root word ge, commonly used in the English prefix geo-, means “earth.” This Greek root is the word origin of a good number of English vocabulary words, including geology, geography, and geometry. The Greek root word ge is easily recalled through the English word geology, which is the study of the “earth.”Like this? Build a competent vocabulary with Membean.

The Earth's magnetic field underwent hundreds of reversals during its history. But within a ~40 Myr span (84-125 Ma) during the Cretaceous no reversal happened. For comparison, the second longest chron length during the last 167 Ma is ~5 Myr. Thus, the ~40 Myr long chron is known as a superchron and is called Cretaceous Normal Superchron (CNS). Two other superchrons are now established: the Permian-Carboniferous Reversed Superchron and the Ordovician Reversed Superchron. Why do these superchrons exist? Are they an extreme chron duration of the same statistical distribution? Or, do superchrons reflect a distinct dynamo regime separate from an oft-reversing regime. Are the onset and end of superchrons triggered by changes in the physical conditions of outer core convection? For example, instabilities within the convection in the outer core are suspected to trigger reversals. A `low energy' geodynamo during the superchron could stem from less turbulent convection. But also the concept of a `high energy' geodynamo during a superchron is conceivable: stronger convection would stabilize the field and increase the field intensity. These different dynamo regimes could be be triggered by changing the temperature conditions at the core mantle boundary (CMB), for example with the eruption of deep mantle plumes or the descent of cold material such as subducted slabs. Insights into past geodynamo regimes can be learned primarily from two paleomagnetic methods: paleosecular variation (variation in field directions) and paleointensity. For the former, we collected 534 samples for a paleosecular variation study from a 1400 m-long, paleontologically well-described section in northern Peru. Thermal demagnetization isolates stable magnetization directions carried by greigite. Arguments are equivocal whether this remanence is syn-diagenetic, acquired during the Cretaceous normal superchron, or a secondary overprint, acquired during a chron of solely normal polarity in the upper Cenozoic, yet pre-Bruhnes (>800 kyr). We explore the ramifications on the S value, which quantifies paleosecular variation, that arises from directional analysis, sun compass correction, bedding correction, sampling frequency, outlying directions and different recording media. The sum of these affects can readily raise the S value by more than 20%. S values from northern Peru are indistinguishable from other S values for the Cretaceous normal superchron as well as those for the last 5 Ma. Summing over all the potential uncertainties, we come to the pessimistic conclusion that the S value is an unsuitable parameter to constrain geodynamo models. Alternatively, no statistical difference in paleosecular variation exists during much of the Cretaceous normal superchron and during the last 5 Ma. Even though the S value might be unsuitable, we wanted to understand why the S value is latitude dependent. The origin of this latitude dependency is widely attributed to a combination of time-varying dipole and non-dipole components. The slope and magnitude of S are taken as a basis to understand the geomagnetic field and its evolution. Here we show that S stems from a mathematical aberration of the conversion from directions to poles, hence directional populations better quantify local estimates of paleosecular variation. Of the various options, k is likely the best choice, and the uncertainty on k(N) was already worked out. As we came to the pessimistic conclusion that the S value might not be the best parameter to quantify the `energy state' of the geodynamo during a superchron, we also carried out a paleointensity study on 128 samples from volcanic rocks in Northern Peru and Ecuador. Oxidation of the remanence carriers was a problem. Only one site gave reliable results. Two methods of paleointensity determination were applied to these rocks. The results of both methods agree quite well with each other and also with previous studies from other sites. Our results suggest that the field intensity towards the end of the superchron seems to quite similar to today's magnetic moment. Thus, it can be concluded that the `energy state' of the geodynamo was not substantially different during the Cretaceous Normal Superchron compared to reversing times. Why do superchrons exist? One possible explanation is that paleomagnetism is not able to resolve different energy states of the geodynamo, neither with paleosecular variation nor with paleointensity. This was suggested by some dynamo simulations in which the heat flux across the core-mantle boundary was kept the same, but the resulting paleosecular variation, paleointensity and frequency of reversals differed a lot. Another possible explanation is that a superchron is an intrinsic feature of the distribution of magnetic polarity chron lengths. Thus, no changes of the convection in the outer core are needed to trigger a superchron.