Indian Plate Movement | Earthquake and Tsunami Risk Zones
Vol NO: Vol. 11, Issue 64, pp 6-12,
"Identifying Tsunami Risk ZonesÂ The concept of plate tectonics is the most satisfying explanation for a majority of earthquakes. The basic idea of plate tectonics involves earthâ€™s outermost part, the lithosphere (100-200 km thick), which consists of several large and fairly stable slabs - the plates. Boundaries of these plates are the seismic belts of the world. At the mid oceanic ridges, upwelling of lava is a continual process. This molten rock creates new sea floor on either side of the ridge and these mid-oceanic ridges thus constitute the spreading zones of the earth or divergent plate boundaries. Since the earthâ€™s size remains the same over a long period of geological time, the moving plates must be absorbed at some places. The burial grounds of plates - the convergent plate boundaries, are believed to be the ocean trenches, where the plates plunge into the earthâ€™s interior. This process is known as subduction - asÂ happens along the Andaman-Sumatra trench, the Japan trench, the Chile trench and so on (Fig 2a). The other type of convergent plate boundary forms the continent-continent collision zone - as happens in the Himalaya, where the Indian plate is on a head-on co
The Indian plate, separated from the Antarctic, started moving to the north northeast about 180 million years ago. The present day movement of the Indian plate from the Carlsberg spreading ridge results in collision in the Himalaya and subduction in the Andaman-Sumatra. These plate margins, therefore, are the major seismic belts of the moving Indian plate.
"Prof J R Kayal is CSIR Emeritus Scientist, Jadavpur University, Kolkata, firstname.lastname@example.org. Reprint Vol. 11, Issue 64, pp 6-12, Geography and You."