Cameroon line

There is a long line of volcanoes.

Some are islands in the sea. Some are mountains on the land.

The islands are home to many birds. They also have special plants. These plants grow there and nowhere else.

The mountains on land are very cool. The air is not as hot there. This is because they are so high.

Some volcanoes are now quiet. They have old holes in them. These holes filled with water. They are now pretty lakes.

This long line is a very special place.

The Cameroon line is a long chain of volcanoes.

Some volcanoes are islands in the ocean. Others are mountains on the African mainland. This line forms a natural border between Nigeria and Cameroon.

The islands include Annobón, São Tomé, Príncipe, and Bioko.

These islands have tropical weather. They are home to many unique plants and birds. Some of these animals live nowhere else on Earth. For example, São Tomé has special birds like the São Tomé ibis.

On the mainland, the line includes Mount Cameroon. It also includes the Western High Plateau. This area has many mountains. Some volcanoes are now quiet. These dead volcanoes have holes in them. These holes filled with water to make crater lakes.

One lake is called Lake Oku. Other lakes, like Lake Barombi Mbo, have many special fish. The high mountains are much cooler than the low lands. The volcanic rocks also make the soil very rich for farming.

The Cameroon line is a long and unusual chain of volcanoes.

It stretches from the ocean all the way to the African mainland. This line includes islands in the Gulf of Guinea and mountains near Lake Chad. It even forms a natural border between eastern Nigeria and Cameroon. Geologists find this line very strange. This is because it goes through both the ocean and the continental crust.

This chain works by creating different landforms as it moves. In the ocean, it forms six volcanic swells. Some of these swells are islands, while others are seamounts under the water. From the southwest to the northeast, the islands are Annobón, São Tomé, Príncipe, and Bioko. On the mainland, the line starts at Mount Cameroon. It then moves northeast into a group of mountains called the Western High Plateau.

Some volcanoes here are now quiet. When they stopped erupting, holes called craters formed. These holes often filled with water to create beautiful crater lakes.

Scientists have studied this line for a long time. They use different ideas to explain why these volcanoes exist. One idea involves a feature called the Central African Shear Zone. This is a long line that runs under the mainland part of the volcanoes. Some experts believe the line is linked to how South America and Africa separated. This split happened about 115 million years ago.

Many specific places make up this volcanic line. Annobón is the southernmost island and belongs to Equatorial Guinea. São Tomé is a massive shield volcano that rises from the Atlantic floor. Its oldest rocks are 13 million years old. Bioko is the largest island in the chain. It has three shield volcanoes, including Santa Isabel. On the mainland, Mount Cameroon erupted as recently as the year 2000.

The Oku Massif is also a very high mountain in the region.

These volcanoes create special homes for living things. Because many islands were always isolated, they have unique plants and birds. On São Tomé, you can find the São Tomé ibis.

The high mountains on the mainland are much cooler than the lowlands. This creates different environments like forests and grasslands. The volcanic activity also makes the soil very rich. This fertile soil helps people grow crops like cocoa and coffee.

The Cameroon line is a massive, continuous chain of volcanoes.

It stretches from the Atlantic Ocean to the African mainland. The chain includes islands in the Gulf of Guinea and mountains near Lake Chad. It also forms a natural border between eastern Nigeria and the West Region of Cameroon. Geologists find this line unusual. This is because it extends through both the ocean and the continental crust.

In the ocean, the line creates six volcanic swells. Some of these swells are islands, while others are seamounts under the water. From the southwest to the northeast, the island groups are Annobón, São Tomé, Príncipe, and Bioko. On the mainland, the line begins with Mount Cameroon on the coast. It then moves northeast into the Western High Plateau. This plateau includes the Cameroonian Highlands forests. Further inland, the line includes the Manengouba, Bamboutu, and Oku Massif volcanoes.

Annobón is the southernmost island in the chain. It is an extinct volcano that rises from deep water. The island belongs to Equatorial Guinea. Its average temperature is 27°C, and it has very little seasonal variation. Most rain falls between November and May. São Tomé is a massive shield volcano. A shield volcano is a wide volcano built by flowing lava. It rises from the Atlantic floor, over 4,000 meters below sea level. The oldest rocks on São Tomé are 13 million years old.

Príncipe is a smaller island located near São Tomé. Volcanic activity on Príncipe stopped around 15.7 million years ago. The island has been deeply eroded over time. This erosion left behind spectacular towers of phonolite, which is a type of volcanic rock. Bioko is the largest island in the Cameroon line. It sits on the continental shelf near the coast of Cameroon. Bioko has three basaltic shield volcanoes. These volcanoes join together at their lower levels. One volcano, San Carlos, has a broad summit caldera. A caldera is a large crater formed when a volcano collapses.

Geologists have different theories about why this line exists. One major feature is the Central African Shear Zone. This is a long lineament, or structural feature, that runs under the mainland section. The coastline of the line roughly matches the Borborema province in Brazil. This connection exists because Africa and South America began to separate 115 million years ago. Some researchers believe the volcanoes are linked to this ancient separation. The shear zone is visible in the Foumban Shear Zone. This area was active during the Cretaceous period.

This volcanic activity has created many unique environments. Because islands like São Tomé and Príncipe were never connected to Africa, they have unique species. For example, São Tomé has 16 endemic bird species. Endemic means they are found nowhere else on Earth. Three species there are critically endangered: the São Tomé ibis, the São Tomé fiscal, and the São Tomé grosbeak. On the mainland, the high mountains are much cooler than the lowlands. This creates specialized habitats like montane forests.

The volcanoes also impact the land and people. Volcanism has created fertile black and brown soils. These soils are excellent for agriculture. People in the region grow cocoa, coffee, and palm products. On the mainland, the Western High Plateau is a major watershed. This means it is a region where water flows into many rivers. Important rivers like the Manyu and the Nkam rise here. These rivers provide water for much of Cameroon.

However, volcanic history can also be dangerous. In 1986, a crater lake called Lake Nyos released a cloud of carbon dioxide. This gas release killed at least 1,200 people. Mount Cameroon is also an active stratovolcano. A stratovolcano is a tall, conical volcano built by layers of ash and lava. Mount Cameroon erupted as recently as the year 2000.