LA TECTONIQUE DES PLAQUES 1/2
https://tube-sciences-technologies.apps.education.fr/w/3fjE5WoyEXjx4PbJWm4eLp

LA TECTONIQUE DES PLAQUES 1/2
https://tube-sciences-technologies.apps.education.fr/w/3fjE5WoyEXjx4PbJWm4eLp

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This is equally true in the #biotic environment (the “#biosphere”), consisting of microorganisms, plants, animals, and the human body; in #abiotic (lifeless) environments, such as the #geosphere, the #lithosphere, the #hydrosphere, and the #atmosphere; and in the entire #ecosphere, comprising ecosystems composed of biotic and abiotic elements in complex interrelationships. Such ecosystems, large and small, for all their components, also interact in intricate mutual relationships.
Andrew Frederiksen (U. Manitoba) gave us a very clear explanation of a better way to analyze shear-wave splitting as a way to probe the fabric (heterogeneities) of the upper mantle under continents.
The red and orange contours of large split times in British Columbia represent aligned olivine from present-day horizontal mantle flow. Splitting in Alberta represents fabrics formed and preserved from the Precambrian.
#UManitoba #McGillUniversity #Seismology #Lithosphere #Mantle #Olivine
Aufeis (Earth sciences 🌍)
Aufeis is a sheet-like mass of layered ice that forms from successive flows of ground or river water during freezing temperatures. This form of ice is also called overflow, icings, or the Russian term, naled. The term "Aufeis" was first used in 1859 by Alexander von Middendorff following his observations of the phenomenon in northern Siberia. When t...
https://en.wikipedia.org/wiki/Aufeis
#Aufeis #WaterIce #Glaciology #Lithosphere #EarthSciences #GeographyOfTheArctic
The processes that form continental crust from the denser basaltic rocks of the upper mantle may make the lower lithosphere denser than the underlying mantle. One theory holds that the lower lithosphere splits away and sinks into the mantle in a process called foundering. Conclusive evidence of foundering, however, has been hard to come by.
Earth's continents are slowly moving across the planet's surface due to plate tectonics, culminating in regions of crustal expansion and collision. In the latter case, high temperatures and pressures lead to the reworking of the crust, affecting its composition, as well as that of the underlying mantle. Furthermore, when two continental plates collide, distinct topographic features are produced, namely mountain ranges, which are surficial manifests of Earth's thickened crust.