Geography

The Comoro archipelago consists of four main islands aligned along a northwest-southeast axis at the north end of the Mozambique Channel, between Mozambique and the island of Madagascar. Still widely known by their French names, the islands officially have been called by their Swahili names by the Comorian government. They are:

• Njazidja (Grande Comore)
• Mwali (Mohéli)
• Nzwani (Anjouan)
• Mahoré (Mayotte)

The islands' distance from each other (Njazidja is 200 kilometres from Mahoré, 40 kilometres from Mwali, and 80 kilometres from Nzwani) along with a lack of good harbour facilities, make transportation and communication difficult.

The islands have a total land area of 2,235 square kilometres (including Mahoré), and claim territorial waters of 320 square kilometres.

Njazidja

Njazidja is the largest of the Comoro Islands, approximately equal in area to the rest of the islands combined. It is 67 km long and 27 km wide, with a total area of 1,146 square kilometres. The most recently formed of the four islands in the archipelago, it is also of volcanic origin. The national capital has been at Moroni since 1962.

Two volcanoes form the island's most prominent topographic features: La Grille in the north, with an elevation of 1,000 m, is extinct and largely eroded; Kartala in the south, rising to a height of 2,361 m, last erupted in 1977. A plateau averaging 600 to 700 m high connects the two mountains. The Karthala is currently one of the most active volcanoes in the world, with a minor eruption in May 2006, and prior eruptions as recently as April 2005 and 1991. In the 2005 eruption from April 17 to 19, 40,000 citizens were evacuated, and the crater lake previously residing in the volcano's 3 by 4 km. caldera was destroyed. One of the largest remnants of Comoros' once-extensive rain forests is on the slopes of Kartala.

Because Njazidja is geologically a relatively new island, its soil is thin and rocky and cannot hold water. As a result, water from the island's heavy rainfall must be stored in catchment tanks. There are no coral reefs along the coast, and the island lacks a good harbour for ships.

Nzwani

Nzwani, triangular shaped and 40 km from apex to base, has an area of 424 square kilometres. Three mountain chains (Sima, Nioumakele and Jimilime) emanate from a central peak, Mtingui (1,575 meters), giving the island its distinctive shape. Older than Njazidja, Nzwani has deeper soil cover, but over-cultivation has caused serious erosion. A coral reef lies close to shore; the island's capital of Mutsamudu is also its main port.

Mwali

Mwali, with its capital at Fomboni, is 30 km long and 12 km wide, with an area of 290 sq km. It is the smallest of the four islands and has a central mountain chain reaching 860 m at its highest.

Mahoré

Mahoré, geologically the oldest of the four islands, is 39 km long and 22 km wide, totalling 375 sq km, and its highest points are between 500 and 600 m above sea level. Because of greater weathering of the volcanic rock, the soil is relatively rich in some areas, and its well-developed coral reef that encircles much of the island ensures protection for ships and a habitat for fish.

Dzaoudzi, capital of Comoros until 1962 and now Mahoré's administrative centre, is located on Pamanzi, (French: Petite-Terre), a rocky outcropping off the east shore of the main island. Dzaoudzi is linked by a causeway to le Pamanzi, which at 10 km in area is the largest of several islets adjacent to Mahoré.