Tag: earthquakes and volcanoes

Sudden movements of the earth can be noticed during the eruption of a volcano. Sudden movements, caused by sudden endogenetic forces coming from deep within the earth, cause such sudden and rapid events that these cause massive destruction at and below the earth's surface. These forces work very quickly and their results are seen within minutes.

The highest active volcano in the world is Ojos del Salado on the Chile-Argentina border in the Central Andes. It rises to 6887 m / 22,595 ft. It has not erupted in recorded history but is an active volcano.

Volcanic crater is a circular depression in the ground caused by volcanic activity. It's typically a basin, circular in form within which occurs a vent from which magma erupts as gases, lava, and ejecta. A crater can be of large dimensions, and sometimes of great depth.

Volcanic activity frequently occurs at the boundaries of the Earth's tectonic plates which are a series of large moving blocks. The movement of these plates plays a significant role in the type of volcano formed, which influences its shape. If the movement is smaller, they leads to volcanic eruptions. Larger movements may lead to earthquakes.

Aconcagua is the highest mountain outside Asia, at 6,961 metres and by extension the highest point in both the Western Hemisphere and the Southern Hemisphere. Aconcagua is of volcanic origin, but it is not an active volcano and cab be considered as extinct.

When a volcano ejects acid lava, they are loud and violent usually because of the explosive pressures building up in magma. They eject acid lava, ash, gases and rock fragments. They are dangerous as materials can rain down on settlements. Ex: Eruptions at Krakatoa in Indonesia.

Mount Kenya is the second highest mountain in Africa, after Kilimanjaro. Mount Kenya is a stratovolcano created approximately 3 million years after the opening of the East African rift. Before glaciation, it was 7,000 m high. It was covered by an ice cap for thousands of years. This has resulted in much eroded slopes and numerous valleys radiating from the centre.

An active volcano is a volcano that has had at least one eruption during the past 10,000 years. An active volcano might be erupting or dormant.

An erupting volcano is an active volcano that is having an eruption...

A dormant volcano is an active volcano that is not erupting but supposed to erupt again.

An extinct volcano has not had an eruption for at least 10,000 years and is not expected to erupt again in a comparable time scale of the future.

The above classification is based on the frequency of eruption while the classification as a composite volcano is based on the structure of the volcano thus option C is the right answer.

Mt Vesuvius is a volcano located in Italy which had last recorded eruption in 1944, hence A is the correct answer. It has a long history of a number of eruptions in recorded history thus it is considered as an active volcano.

• Mt Kilimanjaro is a dormant volcano in Tanzania. Hence C is the correct option.
• It is also the highest mountain of Africa.