How do shield volcanoes formed at hotspots?

As hotspot material rises, the pressure drops so the hotspot begins to melt producing magma. In an oceanic hotspot environment, for example Hawaii, dark, silica-poor basalt magma is produced. The runny basalt forms broad sloping shield volcanoes (Fig. 6).

What is a volcanic hotspot and how is it formed?

In geology, a hotspot is an area of the Earth’s mantle from which hot plumes rise upward, forming volcanoes on the overlying crust. When such a plume rises into the shallow mantle, it partially melts and the melt may then rise to the surface where it can erupt as a hotspot volcano.

How intraplate or hotspot volcanoes can form?

A small amount of geologic activity, known as intraplate activity, does not take place at plate boundaries but within a plate instead. Mantle plumes are pipes of hot rock that rise through the mantle. The release of pressure causes melting near the surface to form a hotspot. Eruptions at the hotspot create a volcano.

Are shield volcanoes formed by hotspots?

Shield volcanoes are found worldwide. They can form over hotspots (points where magma from below the surface wells up), such as the Hawaiian–Emperor seamount chain and the Galápagos Islands, or over more conventional rift zones, such as the Icelandic shields and the shield volcanoes of East Africa.

How do hotspot volcanoes form GCSE?

Hotspots are places where the magma rises up through the crust. They are caused by a static source of magma, often away from plate margins. As the plate moves away from the hotspot, a new volcano island will form.

How do volcanoes form what are its two main processes?

Volcanoes are formed when magma from within the Earth’s upper mantle works its way to the surface. At the surface, it erupts to form lava flows and ash deposits. Over time as the volcano continues to erupt, it will get bigger and bigger.

How are hotspot volcanoes formed quizlet?

A hotspot forms when a plume of magma rises from the mantle and melts through whatever crust is above it. This new magma tries to reach the curface and creates a volcano. But when the tectonic plate shifts, new crust is suddenly above the hotspot, and a new volcano forms. This is how hotspot volcanoes form.

How do hotspot volcanoes work?

A volcanic “hotspot” is an area in the mantle from which heat rises as a thermal plume from deep in the Earth. High heat and lower pressure at the base of the lithosphere (tectonic plate) facilitates melting of the rock. This melt, called magma, rises through cracks and erupts to form volcanoes.

Why do hotspot volcanoes form in lines?

hot spot. Hot spot volcanoes occur far from plate boundaries. Because the hot spot is caused by mantle plumes that exist below the tectonic plates, as the plates move, the hot spot does not, and may create a chain of volcanoes on the Earth’s surface.

Why are hotspots formed?

What causes volcanoes to form in hot spots?

Hotspots occur when one of the Earth’s plates moves over an unusually hot part of the Earth’s mantle. These hot areas are usually relatively stationary and result in large amounts of magma rising up, piercing a hole in the plate to form a volcano. As the plates move, a series of volcanoes can form.

How are hotspot volcanoes different from island arc volcanoes?

Hotspot volcanoes are considered to have a fundamentally different origin from island arc volcanoes. The latter form over subduction zones, at converging plate boundaries. When one oceanic plate meets another, the denser plate is forced downward into a deep ocean trench.

What makes a volcanic hotspot a thermal plume?

Hotspot Volcanism: Thermal Plume. What is a volcanic hotspot? A volcanic “hotspot” is an area in the mantle from which heat rises as a thermal plume from deep in the Earth. High heat and lower pressure at the base of the lithosphere (tectonic plate) facilitates melting of the rock.

How is Hawaii a hotspot for tectonic plates?

National Park Service sites in Hawaii provide an exceptional glimpse at landscapes developing as a tectonic plate capped by thin oceanic crust moves over a hotspot. Broad, gently sloping shield volcanoes develop on the seafloor as the Pacific Plate moves over the Hawaiian Hotspot.