Q1.
Pick any two plates from the map above and complete the table given below. (Name of the plate | Continents | Ocean)
Answer
Read the plate outlines and the arrows in Fig. 2.3 first, then fill the table. Any two plates are acceptable — here are two worked examples, with the rest of the major plates given so you can check whichever pair you chose.
| Name of the plate | Continents | Ocean |
|---|---|---|
| Indo-Australian plate | Asia (the Indian subcontinent) and Australia | Indian Ocean |
| South American plate | South America | Atlantic Ocean (its western half) |
The other major plates in Fig. 2.3, for reference:
| Name of the plate | Continents | Ocean |
|---|---|---|
| North American plate | North America, Greenland | Atlantic Ocean (western half), part of the Arctic Ocean |
| Eurasian plate | Europe and most of Asia | Atlantic Ocean (eastern half), Arctic Ocean |
| African plate | Africa | Atlantic Ocean (eastern half) and the western Indian Ocean |
| Pacific plate | Almost none — a small strip of North America along the Californian coast | Pacific Ocean |
| Antarctic plate | Antarctica | Southern Ocean, and the southern edges of the Pacific, Atlantic and Indian Oceans |
What the two rows tell you: the Indo-Australian and South American plates both carry land and sea floor, so they are mixed plates in the chapter's three-fold classification. The Pacific plate is the clearest oceanic plate — it is almost entirely ocean floor. That is why the Pacific rim, where this heavy oceanic plate meets lighter continental plates, is ringed by volcanoes and earthquakes.
Check it yourself on the map: read the arrows for the plate you picked. Over India the arrows on the Indo-Australian plate point north and north-east, straight into the Eurasian plate — which is precisely where the Himalaya stands. On either side of the mid-Atlantic the arrows point away from each other, one set west and one set east. Around Antarctica they point outwards in every direction.