What are the characteristics of a shield volcano and how are they formed?

A shield volcano is built mainly out of basaltic lava of low viscosity. The lava flows out, cools and hardens, adding to layers of cooled and hardened lava underneath it. This process creates a gradual increase in elevation over time resulting in the formation of shield volcanoes.

Which best describes a shield volcano?

A shield volcano is a wide volcano with shallowly-sloping sides.

Which of the following are characteristics of shield volcanoes any two points?

Shield volcanoes

Flow after flow pours out in all directions from a central summit vent, or group of vents, building a broad, gently sloping cone of flat, domical shape, with a profile much like that of a warrior’s shield.

Are shield volcanoes explosive?

Shield volcanoes are fairly low volcanoes with rounded tops. When a shield volcanoe erupts, it’s not very explosive and it tends to be mostly in the form of a liquid lava that flows down the side of the volcano and solidifies to form the next layer of the volcano’s surface.

What is the shape of a shield volcano?

Shield volcanoes are shaped like a bowl or shield in the middle with long gentle slopes made by the lava flows. Examples include the volcanoes in Hawaii and Mount Etna.

How tall are shield volcanoes?

1,500 to 2,000 ft
Typical shield volcanoes found in California and Oregon measure 3 to 4 mi (5 to 6 km) in diameter and 1,500 to 2,000 ft (500 to 600 m) in height, while shield volcanoes in the central Mexican Michoacán–Guanajuato volcanic field average 340 m (1,100 ft) in height and 4,100 m (13,500 ft) in width, with an average slope …

What is the largest shield volcano on Earth?

From sea floor to peak, Mauna Loa, on Hawaii’s Big Island, is the tallest shield volcano on Earth.

What are shield volcanoes made of?

Shield volcanoes are usually constructed almost entirely of basaltic and/or andesitic lava flows which were very fluid when erupted.

Are shield volcanoes flat?

Shield volcanoes are tall and broad with flat, rounded shapes. They have low slopes and almost always have large craters at their summits. The Hawaiian volcanoes exemplify the common type of shield volcano.

What causes a shield volcano?

Shield volcanoes are the result of high magma supply rates; the lava is hot and little-changed since the time it was generated. Shield volcanoes are the common product of hotspot volcanism but they can also be found along subduction-related volcanic arcs or all by themselves.

How wide are shield volcanoes?

The largest shields, however, are over 700 km in diameter and up to 5.5 km in height. For reference, Mauna Loa is ~120 km across at its base, and it has a total height of ~8 km (from the sea floor). Thus, the large Venusian shields are broader, but much flatter then the largest shield volcanoes on Earth.

What type of magma do shield volcanoes have?

Shield volcanoes are composed almost entirely of relatively thin lava flows built up over a central vent. Most shields were formed by low viscosity basaltic magma that flows easily down slope away form the summit vent.

Why do shield volcanoes have wide bases?

Shield Volcanoes, Cinder-Cone Volcanoes and Composite Volcanoes. Why do shield volcanoes have wide bases? The lava is so runny, it spreads over a wide area.

Why do shield volcanoes never grow tall?

Shield Volcanoes

These volcanoes can cover large areas but never grow very tall. The reason these volcanoes tend to flatten out is due to the composition of the lava that flows from them, which is very fluid. This more fluid lava spreads out in all directions but cannot pile up in steep mounds.

Why do shield volcanoes have weak eruptions?

Answer and Explanation: Shield volcanoes have weak eruptions because the material that comes out of a volcano has low viscosity.

Where are shield volcanoes?

Types of Volcanoes: Shield volcanoes

Mid-ocean islands such as Hawaii, the Galapagos, Reunion, or Bermuda are formed by basalt, the most basic and most fluid, less viscous of all types of common lava. Geochemically, various types of basalts (tholeiite, alkaline etc.)