Venus’ Surface Tectonics is More Like Pack ice on Earth

Planets move in mysterious ways.  Or at least their surfaces do.  Earth famously has a system of tectonic plates that drives the movement of its crust.  Those plate tectonics are ultimately driven by the flow of material in the mantle – the layer directly below the crust.  Now, scientists have found a slightly different deformation mechanic on our nearest sister planet – Venus.

The research, carried out by Dr. Paul Byrne of North Carolina State University and his colleagues, used data from NASA’s Magellan spacecraft which visited Venus back in the 90s.  While orbiting the planet, the probe collected a radar map of its surface, which is obscured by a thick atmosphere at wavelengths visible to the human eye.

In part of that radar map, the researchers noticed something interesting – a series of blocks where the crust of the planet (known as the “lithosphere”) looked like it had moved.  This finding flew in the face of the convention wisdom of Venus, which held that Venus’ lithosphere was immobile.  

As any good scientist knows, if the data disproves an old theory, a new theory is required.  So the team set out modeling the deformation to see if they could figure out what might have caused it.  The answer appears to be that he deformation is caused by the slow movement of the planet’s interior.  

What’s more, the researchers also think the process that caused these deformations might still be ongoing.  Venus famously has active volcanoes that are another way its surface deforms itself.  These volcanoes form lava plains, which are relatively young in geological terms.  Some of those lava plains had evidence of the deformation in Magellan’s data, implying that, even after having been recently resurfaced due to volcanic activity, Venus’ lithosphere is deformed again by its active interior.

That active interior causes deformations that interact similarly to ice sheets that are broken up and jostled on top of each other.  Sometimes those create even small ice sheets or jagged patterns, and the patterns that result from that jostling look similar to what the researcher saw on the lava plains of Venus.

Luckily they won’t be the last ones to look – a group of three new missions will be visiting our sister planet in the coming decades.  They will sport new and improved sensors, including one (VERITAS) whose primary mission is to accurately map the planet’s surface.  It will undoubtedly see the formations that Magellan found, but maybe higher resolution data will lead yet more insights.

Learn More –
NCSU – ‘Pack Ice’ Tectonics Reveal Venus’ Geological Secrets
PNAS – A globally fragmented and mobile lithosphere on Venus
BBC – Signs of geological activity found on Venus
Technology Review – Scientists might have spotted tectonic activity inside Venus

Lead Image –
Picture of one of the large blocks in Venus’ low-lands that they found, known as Nüwa Campus
Credit – Paul K. Byrne and Sean C. Solomon