Viscoelastic Isostasy of Earth’s crust and mantle
Project Description

Isostasy (Greek ísos “equal”, stásis “standstill”) is the state of gravitational equilibrium between Earth’s crust and mantle such that the crust “floats” at an elevation that depends on its thickness and density.

This concept explains how different topographic heights can exist at Earth’s surface. When a certain area of Earth’s crust reaches the state of isostasy, it is said to be in isostatic equilibrium. Isostasy is not a process that upsets equilibrium, but instead is one which restores it. Earth is a dynamic system that responds to loads in many different ways. Isostasy provides an important view of the processes that are happening in areas that are experiencing vertical movement. Certain areas (such as the Himalayas) are not in isostatic equilibrium, which has forced researchers to identify other reasons to explain their topographic heights. Although originally defined in terms of continental crust and mantle, it has subsequently been interpreted in terms of lithosphere and asthenosphere.

In the simplest example, isostasy is the principle of buoyancy wherein an object immersed in a fluid is buoyed with a force equal to the weight of the displaced fluid. On a geological scale, isostasy can be observed where Earth’s strong crust or lithosphere exerts stress on the weaker mantle or asthenosphere, which, over geological time, flows laterally such that the load is accommodated by height adjustments.

The general term ‘isostasy’ was coined in the year 1889 by the American geologist Clarence Dutton.

This animation was created to visualize this concept for the Polar Earth Observing Network’s (POLENET) research in the polar regions. The project focuses on collecting GPS and seismic data from autonomous systems deployed at remote sites spanning much of the Antarctic and Greenland ice sheets. GPS and seismic measurements together provide a means to answer critical questions about ice sheet behavior in a warming world.

The unprecedented scale of the POLENET sensor network will allow investigation of systems-scale interactions of the solid earth, the cryosphere, the oceans and the atmosphere.

POLENET data will enable new studies of the inner earth, tectonic plates, the earth’s magnetic field, climate and weather, and the solar wind, and will lead to as yet unimagined discoveries about the critical polar regions of our planet.

Project Details
Customer:
The Polar Earth Observing Network (POLENET)
Skills:
Adobe Photoshop, Flash, Final Cut Pro
Date:
June 30, 2010