Tuesday, June 12, 2012

Siberian North America

Contrary to a popular assumption, the major tectonic plates of Planet Earth do not correspond directly to the contour of the continents and oceans for which they are named. The North American Plate, for example, extends westward from the mid-Atlantic Ridge, thereby including the western half of Iceland, the western half of the Atlantic Ocean, Greenland, Canada, the Continental U.S., Cuba, the Bahamas, the Gulf of Mexico, the northern Caribbean and the country of Mexico. Its western edge generally follows the west coast of Mexico, the U.S. and Canada (excluding the Baja and Southern California, which are on the Pacific Plate), curving westward below Alaska and its Aleutian Chain and then dipping southward to take in the northern islands of Japan; from there, the western edge of the North American Plate angles NNW, cutting across eastern Siberia.

The Chersky Range of eastern Siberia, trending NW to SE, is a swath of parallel ridges and deep gorges; geologically, these mountains represent a compression zone between the North American and Eurasian Plates and are thus prone to frequent earthquakes. Extending northwestward from the Chersky Range is the Laptev Sea Rift, cutting through the Laptev Shelf on the northern coast of Siberia; this rift is a continental extension of the Gakkel Ridge, the spreading zone of the Arctic Ocean which, across the globe, is continuous with the Mid-Atlantic Ridge. The North American and Eurasian Plates are thus diverging along the Mid-Atlantic/Gakkel Ridge and colliding at the Chersky Range.

Of more significance to politically-minded, nationalistic humans, eastern Siberia, including the Kamchatka Peninsula, is on the North American Plate while Southern California and Hawaii are on the Pacific Plate, tied tectonically to Tahiti, the Soloman Islands and Southern New Zealand. Perhaps, if we paid more attention to the geology of our planet and less to our cultural differences, we might be more devoted to our common welfare.