Shield Volcano: Definition, Examples, characteristics, Diagram

A shield volcano is a type of volcano characterized by its broad, gently sloping profile resembling a warrior’s shield. These volcanoes are primarily built by the accumulation of low-viscosity basaltic lava flows. The lava flows are often highly fluid, allowing them to travel long distances from the vent before solidifying.

In this article, We have covered the Shield Volcano Definition, Examples, Formation, Location Characteristics, and many more in Detail.

Let’s dive right in.

Shield Volcano

Shield Volcano Definition

The largest volcanoes in terms of volume with a diameter of up to hundreds of kilometres are known as Shield Volcanoes. The name of the shield volcano is derived from its appearance. In comparison with the two other types of volcanoes, it is significantly flatter while having a larger area. When viewed from above, it resembles a warrior’s shield with long, gently sloping sides and a slightly raised centre.

What is a Shield Volcano?

Shield volcanoes are a type of volcano white erupts basalt lava. As basalt has a low viscosity (more watery), it can flow on the surface easily. During the eruption of these types of volcanoes, lava flows outwards at large distances. Shield Volcano derived its name from its shape, which looks quite similar to a warrior’s shield seen from the side. It’s much wider than it is high. Shield volcanoes are built up of many flows of runny lava, each of which is relatively thin, only a few meters thick. A shield volcano is formed when low viscosity, runny lava from a volcano extends far from its source and takes the form of a volcano with gentle slopes. Liquid basaltic lava flows compose the majority of shield volcanoes.

Examples of Shield volcanoes

Few examples of Shield Volcano are:

• Kilauea and Mauna Loa
• Fernandina
• Karthala
• Erta Ale Tolbachik
• Masaya

Location of Shield Volcano

Shield volcanoes are located anywhere where there is basaltic (or even sometimes andesitic) volcanism, including at oceanic hot spot tracks for example in the Hawaiian Islands. Sometimes they are also present at mid-ocean spreading ridges.

Characteristics of Shield Volcano

The following are the characteristics of Shield Volcano:

• Basaltic magma, which has a high temperature and a very low silica and gas content, is what makes up shield volcanoes.
• Runny, non-acidic lava flows from shield volcanoes.
• Shield volcanoes have gentle edges because the lava that has erupted is still pliable and flows for a long time before solidifying.
• The intervals between eruptions are shorter, and the explosions are not as powerful.
• On divergent plate borders, shield volcanoes can be found.
• A dome-shaped surfaces that harden quickly underground lava tubes fewer severe eruptions spaced out more widely.

Shield Volcano Formation

Lava is released from centralised vents in the Earth’s crust and flows down the sides of the volcano’s slopes as a low-viscosity flow over time. Shield Volcanoes are formed when this basaltic lava flow grows in bulk. Shield volcanoes are shaped differently from other types of volcanoes by the basaltic lava that forms them. The shield volcano’s surface is broad because to its rapid flow and increased coverage of land. A new layer of hardened lava is created on top of the previously formed layer by additional basaltic lava flowing over the surface during each eruption. The shield volcano is formed when these layers gradually rise. As the lava flows, the volcano’s elevation climbs with time, resulting in an increasingly wider surface.

Shield Volcano Eruption

The Volcanic Explosivity Index (VEI) typically ranges from 0 to 1, with most shield volcano eruptions being nonexplosive (effusive) and characterised by a Hawaiian-style eruption. Lava flows become fluid during these eruptions, and fire fountains could result. Lava flows can cover enormous areas quickly and are facilitated by high eruption rates.

More powerful pheatic or phreatomagmatic eruptions are possible, but they are uncommon. Throughout Kīlauea’s history, there have been periodic, powerful phreatomagmatic explosions. Both the first and second interludes spanned roughly 1000 and 1800 CE, respectively. Additionally, the Kīlauea caldera saw explosive eruptions in 1924.

Components of Shield Volcano

Shield volcanoes consist of multiple components:

• First, the magma chamber, or magma reservoir, is situated near the volcano’s base.
• From there is the magma conduit, the main pipe that connects to a vent in the volcano’s top, or crater.
• Lava flows over the volcano’s slopes during eruptions due to secondary conduits known as dikes.
• More lava can flow from the dikes and magma conduit throughout the volcano through sills, or veins.
• Upon solidifying on the surface, lava forms a strata layer. This is the outermost layer of the volcano’s hardened surface.
• The lava flows through an open volcano. To let gases escape while the lava flows, vents known as fumaroles might occasionally occur throughout the volcano. These fumaroles are capable of forming lava lakes.

Difference between Shield volcano & Composite Volcano

The following table lists the differences between Shield and Composite Volcano:

Shield Volcano	Composite Volcano
They are made up of basaltic magma that has a high temperature and low content of silica and dissolved gases. Less explosive activity occurs when magma of this kind reaches the surface.	They are made of low-temperature andesitic magma with a high silica and dissolved gas concentration. When this type of magma will reach the surface, it will probably blow.
Shield volcano basaltic lava is fluid in nature and is of low viscosity.	Here, lava is acidic in nature and is of high viscosity
Smooth sides are the result of large amount of lava flowing before it gets solidifies.	Composite volcanoes steep slopes are the result of the lava flowing through a short distance before it gets solidifies.
Eruptions are less violent.	Violent eruptions.
Shorter duration during eruptions.	Longer duration during eruptions.

Conclusion on Shield Volcano

A shield volcano is a wide volcano with sloping sides that is mostly generated by lava flowing from the summit vent in the centre. In contrast to composite volcanoes, which generate towering mountains with conical peaks, shield volcanoes are the largest volcanoes on Earth. Rather, they resemble flat warrior’s shields on Earth and are large, gently sloping volcanoes.

FAQs on Shield Volcano

Where is the most famous shield volcano?

Mauna Loa is the largest shield volcano found on the Island of Hawaii.

What are the three types of volcanoes?

The most well-known types of volcanoes are cinder cones, composite volcanoes and shield volcanoes.

What are two shield volcanoes?

Mauna Kea and Mauna Loa are shield volcanoes.

What is the oldest volcano ever?

The world’s oldest identified volcano is believed to be the “Puy de Dome” in the Massif Central in France.

What are 3 shield volcano examples?

Shield volcano examples are following: Kilauea and Mauna Loa , Fernandina , Karthala, Erta Ale, Tolbachik, Masaya.

Where is the largest shield volcano in the world?

Hawaiian volcano Puhahonu is the largest and hottest shield volcano on Earth.