Welcome to the website of The Atlas of the underworld – the first complete mapping of subducted plates in the Earth’s mantle and their geological interpretation.The Earth’s rigid outer shell – the lithosphere – is broken into plates that move relative to one another along discrete plate boundaries – ridges, transforms, and subduction zones. At subduction zone plate boundaries, one plate disappears below another and sinks into the mantle. These sinking plates, called ‘slabs’, are colder than their surroundings, and remain colder for a very long period of time – about 250 million years. As a result, the speed at which seismic waves travel through these bodies of sinking lithosphere is a little higher than from the surrounding hot mantle. Since the 1980’s, the technique of seismic tomography has been developed that provides a 3D image of the seismic velocity structure of the Earth’s crust and mantle, from the surface to the boundary between the mantle and the Earth’s liquid outer core at a depth of 2900 km.Subduction leaves a distinct geological record at the Earth’s surface, in the form of major mountain ranges such as the Andes or the Himalaya, or major volcanic arcs such as the Pacific Ring of Fire. Using these geological records, Earth Scientists have developed ways to determine when and where subduction episodes started and ended. On this website, we provide the current state-of-the-art of the images of slabs in the Earth’s upper and lower mantle, and the geological interpretation of when and where they were subducting. In the main article associated with this website, we use the information provided here to deduct physical properties of the mantle and slabs, and discuss ways to develop reference frames for plate reconstructions of the geological past. On this website, we provide open access to all slabs, organized by location, age, depth, and name.
Robin Edgar
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