lithosphere tagged posts

‘Pack Ice’ Tectonics reveal Venus’ Geological Secrets

Venus
An oblique radar view of the largest block in the Venus lowlands identified by Byrne et al. Complex belts of tectonic structures bound the block, but the interior is much less deformed, hosting lava flows and a handful of impact craters. Image: Paul Byrne, based on original NASA/JPL imagery.

A new analysis of Venus’ surface shows evidence of tectonic motion in the form of crustal blocks that have jostled against each other like broken chunks of pack ice. The movement of these blocks could indicate that Venus is still geologically active and give scientists insight into both exoplanet tectonics and the earliest tectonic activity on Earth.

“We’ve identified a previously unrecognized pattern of tectonic deformation on Venus, one that is driven by interior motion just like on Earth,” sa...

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Magnetic Oceans and Electric Earth

Magnetic oceans and electric Earth

The magnetic field and electric currents in and around Earth generate complex forces that have immeasurable impact on every day life. The field can be thought of as a huge bubble, protecting us from cosmic radiation and charged particles that bombard Earth in solar winds. Credit: ESA/ATG medialab

Oceans might not be thought of as magnetic, but they make a tiny contribution to our planet’s protective magnetic shield. Remarkably, ESA’s Swarm satellites have not only measured this extremely faint field, but have also led to new discoveries about the electrical nature of inner Earth. The magnetic field shields us from cosmic radiation and charged particles that bombard Earth from the Sun. Without it, the atmosphere as we know it would not exist, rendering life virtually impossible...

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Plate Tectonics thanks to Plumes?

Venus as a model: Today this planet looks like the Earth might have looked before the onset of plate tectonics. Credit: NASA/JPL

Venus as a model: Today this planet looks like the Earth might have looked before the onset of plate tectonics. Credit: NASA/JPL

It is common knowledge that Earth’s rigid upper layer called lithosphere is composed of moving plates. But just what mechanism first set plate tectonics into motion still remains a mystery. Scientists have now come up with one possible answer with simulations. But just as in the past, earth scientists still do not understand what triggered plate tectonics in the first place, nor how the first subduction zone was formed. A weak spot in the Earth’s lithosphere was necessary in order for parts of the Earth’s crust to begin their descent into the Earth’s mantle...

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