system for the islands, North Sentinel Island was still highly protected from outside contact. Special permission to allow researchers and anthropologists to visit could be sought. Chau had no special clearance, and knew that his visit was illegal. Although a less restrictive system of approval to visit some of the islands now applies, with non-Indian nationals no longer required to obtain pre-approval with a Restricted Area Permit (RAP), foreign visitors must still show their passport at Immigration at Port Blair Airport and Seaport for verification. Citizens of Afghanistan, China and Pakistan, or other foreign nationals whose origin is any of these countries, still required to obtain a RAP to visit Andaman and Nicobar Islands. Similarly, citizens of Myanmar who wish to visit Mayabunder or Diglipur must also apply for a RAP. In these cases, the permits must be pre-approved prior to arrival in Port Blair. Natural disasters On 26 December 2004, the coast of the Andaman Islands was devastated by a tsunami following the 2004 Indian Ocean earthquake, which is the longest recorded earthquake, lasting for between 500 and 600 seconds. Strong oral traditions in the area warned of the importance of moving inland after a quake and is credited with saving many lives. In the aftermath, more than 2,000 people were confirmed dead and more than 4,000 children were orphaned or had lost one parent. At least 40,000 residents were rendered homeless and were moved to relief camps. On 11 August 2009, a magnitude 7 earthquake struck near the Andaman Islands, causing a tsunami warning to go into effect. On 30 March 2010, a magnitude 6.9 earthquake struck near the Andaman Islands. Geography The Andaman Archipelago is an oceanic continuation of the Burmese Arakan Yoma range in the North and of the Indonesian Archipelago in the South. It has 325 islands which cover an area of , with the Andaman Sea to the east between the islands and the coast of Burma. North Andaman Island is south of Burma, although a few smaller Burmese islands are closer, including the three Coco Islands. The Ten Degree Channel separates the Andamans from the Nicobar Islands to the south. The highest point is located in North Andaman Island (Saddle Peak at ). The subsoil of the Andaman islands consists essentially of Late Jurassic to Early Eocene ophiolites and sedimentary rocks (argillaceous and algal limestones), deformed by numerous deep faults and thrusts with