The Pacific Realm:
Physical Geography

Size
The Pacific Ocean comprises one third of the earth's surface and is larger than all the continents combined! It's land area though is only 192,200 square miles, or less than one half of one percent of the earth's land area. Well over ninety- percent of this land area is the one island of New Guinea. With a population of 4.5 million the country of Papua New Guinea, which occupies the eastern half of the island of New Guinea, contains 70% of the realm's population of 7 million .

Hot Spots
Many of the islands in this realm are volcanic island chains formed above "hot spots" in the ocean crust. Read this USGS site on hotspots and island chain formation: http://pubs.usgs.gov/publications/text/hotspots.html

Atolls
Atolls are low islands made of coral that usually have an irregular ring shape around a central lagoon. See the map of the Palmyra Atoll. The formation of atolls was hypothesized by Charles Darwin ( yes, the evolution guy) to be caused by a coral reef forming around a volcanic island. Later the volcanic island begins to sink as the coral ring continues to grow. Eventually the volcanic island submerges and all that is left is the coral ring.

OPTIONAL:
For more information on Darwin and atolls see: http://pauillac.inria.fr/~clerger/Darwin.html