Carissimi Associati SGI,
Carissimi Soci Società Associate,
su indicazione del Prof. Rodolfo Carosi (Università di Torino e Presidente SGI) vi segnaliamo l'ultimo podcast di Geology Bites (Conversations about geology with researchers making key contributions to our understanding of the Earth and the Solar System):
Di seguito troverete il messaggio dell'ideatore, Oliver Strimpel, e il link al sito web di Geology Bites.
Cordiali saluti,
La Segreteria SGI
Hello, listeners,
In the latest episode of Geology Bites, I talk to Steve Jacobsen, a mineral physicist at the University of Colorado Boulder. His work aims to find out how common minerals behave under extremes of temperature and pressure, such as those found within the Earth and the planets.
In the podcast, we talk about three extreme environments: the core-mantle boundary, the mantle transition zone, and the surface of the Moon. At the core-mantle boundary, one interesting finding concerns the ultra-low velocity zones (ULVZs), which have come up in several previous podcast episodes. Although seismic wave velocity normally increases with density, ULVZs have low velocities (hence their name) but higher densities than their surroundings, i.e., the opposite of what one might expect. Jacobsen and his team have found in laboratory experiments that when you increase the fraction of iron relative to magnesium in a silicate, the density goes up, but the shear velocities tend to go down. So rather than (or as well as) partial melting in the ULVZs, we could be seeing variations in iron content.
I hope you enjoy listening.
Oliver