Zamami Island, about two hours west of Naha (Okinawa) by fast ferry, is in the Kerama island group. Among the island's many charms is the fact that it does not host the deadly habu snakes found on Okinawa proper. Yonaguni is also habu-free.
The most common explanation for the fact that some islands are infested with habu and others are not goes like this. The islands that have snakes living on them were once connected. When the land bridges that connected them subsided below sea level, they became independent islands with shared animal populations. The islands that do not have snakes came into being separately, when sub-sea sedimentary rock layers were fractured, tilted, and pushed up above sea level.
Monday, November 7, 2011
The two dark stripes and their discontinuities tell of earthquakes that happened in ancient days. The larger right/left discrepancy is close to one foot. The one above that is a few inches.