Delving inside Earth from space - ESA trying to understand earthquakes and volcanic eruptions

Delving inside Earth from space - ESA trying to understand earthquakes and volcanic eruptions

ESA astronaut André Kuipers is running experiments on the International Space Station that are shedding light on conditions deep inside Earth. Orbiting some 400 km above us, Geoflow is offering insights into the inner workings of our planet.

Descending 3000 km under our feet, Earth’s mantle is a semi-solid fluid under our thin outer crust. The highly viscous layers vary with temperature, pressure and depth.

Understanding how the mantle flows is a major interest for geophysics because it could help to explain earthquakes or volcanic eruptions. Computers can model it, but how can scientists be sure they are correct?



The deepest that humans have ever drilled is just over 12 km, so investigating the mantle directly is out of reach for the immediate future.

Instead of probing Earth’s depths directly, six European teams led by the University of Cottbus in Germany looked to recreate aspects of mantle flow in a laboratory. Experiments simulating these conditions can verify and improve the computer models.

This poses a different problem, however. How can gravity be simulated without Earth’s gravity itself influencing the results?

The solution is to send an experiment to our largest weightless laboratory: the International Space Station.

Planet in a box

ESA sponsored the development of an experiment that mimics the geometry of a planet. Called Geoflow, it contains two revolving concentric spheres with a liquid between them.

The inner sphere represents Earth’s core, with the outer sphere acting as the crust. The liquid, of course, is the mantle.

Free from the influence of Earth’s gravity, a high-voltage electrical field creates artificial gravity for the experiment.

As the spheres rotate slowly and a temperature difference is created between the shells, movement in the liquid is closely monitored. The temperatures can be controlled down to a tenth of a degree.

GEOFLOW_fluid_cell_assembly

André has seen plumes of hotter liquid rising towards the outer shell – as predicted by computer simulations.

Mushroom-like plumes in fluids exposed to strong temperature differences might explain the Hawaiian line of volcanoes in the South Pacific.

A better understanding of our planet is not the only outcome of Geoflow. The results could also benefit industry by improving spherical gyroscopes, bearings and centrifugal pumps, for example.

Source: esa.int

Featued image: Geoflow data from the International Space Station showing how a liquid between two revolving concentric spheres moves as the temperature between the outer and inner sphere changes. Six European teams led by the University of Cottbus in Germany recreated aspects of mantle flow in the Geoflow laboratory. Experiments simulating these conditions can verify and improve computer models. Understanding how Earth’s mantle flows is a major interest for geophysics because it could help to explain earthquakes or volcanic eruptions. The results could also benefit industry by improving spherical gyroscopes, bearings and centrifugal pumps, for example. Credit: ESA

Comments

Carolyn Rose 7 years ago

It turns out in my state of Oklahoma there are many many fault lines thought not to exist. Looking at fault maps it can be seen that Oklahoma is fragmented around it's texas border, with a huge fault rising out of the southeast corner and crossing the whole state up to Kansas centering near Oklahoma city. New faults have been found in the northeast corner. Its all like one big puzzle. Much of southeast Ok is undermined from the time of statehood creating sinking roads, housing, and ever growing sink holes in parts of the state as featured on this web site. Much more focus needs to be on the dangers of living in under- mined areas as earthquakes are almost a daily thing here now.

Post a comment

Your name: *

Your email address: *

Comment text: *

The image that appears on your comment is your Gravatar