We have a team of volcanologists that works on various research projects in locations around the world to help governments and local people to understand volcano behaviour. Volcanic eruptions can be explosive, sending ash, gas and magma high up into the atmosphere, or effusive, producing lava flows and domes. Find out about the different types of volcanic hazards that put human lives, livelihoods or infrastructure at risk of harm. It may seem unwise to choose to live with such a hazardous neighbour as a volcano.
There are a number of reasons why people live alongside volcanoes. Types of volcano Discovering Geology — Volcanoes. When magma erupts at the surface as lava, it can form different types of volcano depending on: the viscosity, or stickiness, of the magma the amount of gas in the magma the composition of the magma the way in which the magma reached the surface Strictly speaking there are two broad types of volcano, a stratovolcano and a shield volcano, although there are lots of different volcanic features that can form from erupted magma such as cinder cones or lava domes as well processes that shape volcanoes.
Why are there different types of volcano? Characteristics of lava domes include the growth of spines. Incandescence of a lava dome at night. You may also be interested in. Discovering Geology Discovering Geology introduces a range of geoscience topics to school-age students and learners of all ages.
Earth hazards The Earth beneath our feet is constantly shifting and moving, and violently with catastrophic and immediate results. Volcanoes We have a team of volcanologists that works on various research projects in locations around the world to help governments and local people to understand volcano behaviour. How volcanoes form How the different types of volcano are formed and the relationship with plate tectonics.
Eruption styles Volcanic eruptions can be explosive, sending ash, gas and magma high up into the atmosphere, or effusive, producing lava flows and domes. Volcanic hazards Find out about the different types of volcanic hazards that put human lives, livelihoods or infrastructure at risk of harm. These are the largest volcanoes on Earth. This is a vertical air photo of the summit caldera of Mauna Loa volcano North is to the left. Notice that the caldera is composed of numerous smaller "cookie-cutter" collapses which have coalesced to form the main caldera.
Notice also that many of the lava flows dark and light are 'a'a and pahoehoe, respectively have been truncated by the caldera margin. This is an indication that they erupted from the volcano summit when the caldera was full. Collapse since then has produced the present caldera. In this manner of collapsing and filling, calderas come and go throughout the active lifetime of a basaltic volcano.
Cinder cones usually have a crater at the summit. Cinder cones are often found near larger volcanoes. Supervolcano eruptions are extremely rare in Earth history. A supervolcano must erupt more than 1, cubic km cubic miles of material, compared with 1.
Helens or 25 km3 for Mount Pinatubo, a large eruption in the Philippines in Not surprisingly, supervolcanoes are the most dangerous type of volcano. Supervolcanoes are a fairly new idea in volcanology. The exact cause of supervolcano eruptions is still debated, however, scientists think that a very large magma chamber erupts entirely in one catastrophic explosion.
This creates a huge hole or caldera into which the surface collapses. Yellowstone sits above a hotspot that has erupted catastrophically three times: 2.
Yellowstone has produced many smaller but still enormous eruptions more recently. Long Valley had an extremely hot and explosive rhyolite explosion about , years ago. An earthquake swarm in alerted geologists to the possibility of a future eruption, but the quakes have since calmed down. A supervolcano could change life on Earth as we know it. Ash could block sunlight so much that photosynthesis would be reduced and global temperatures would plummet.
No one knows when the next super eruption will be. Skip to main content. Tectonic Forces.
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