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Uploaded on:
18/03/2009 05:48:34
Digital Asset
File Size:
98.27 KB
1000 x 773 pixels
3000 views 0 downloads
P number: P551745
Caption: Gouache painting showing creation and destruction of oceanic crust.
Description: The painting is the first of two, showing how oceanic crust (shown in black) is created and destroyed. Magma (molten rock) is erupted along a mid-ocean ridge where it solidifies to become new oceanic crust. As more oceanic crust is created in this way the older, cooler crust moves away from the ridge and millions of years later may eventually be subducted beneath the continents at one or both sides of the ocean. Subduction is the process in which oceanic crust descends into the Earth's mantle. When subduction occurs at the edges of continents (as in this painting) it is marked by major oceanic trenches and the formation of chains of volcanoes known as volcanic arcs in the overlying continent (e.g. the Andes). The processes shown in this painting form part of the theory of plate tectonics. In this theory it is recognised that the Earth's surface is fragmented into tectonic plates (which carry both oceans and continents), which are continually moving across the surface of the planet. The boundaries of these plates interact with each other and are the sites of subduction zones, mid-ocean ridges (both shown in the picture), rift valleys, continental collision zones and transform faults.
Date taken: 01/04/2004
Photographer: Unknown
Copyright statement: NERC
Orientation: Landscape
Size: 98.27 KB; 1000 x 773 pixels; 85 x 65 mm (print at 300 DPI); 265 x 205 mm (screen at 96 DPI);
Average Rating: Not yet rated
Categories: Best of BGS Images/ Artworks  


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