Because Hawaiian volcanoes are formed in the middle of the Pacific plate and not on the edge, the plate tectonic theory by itself doesn’t explain their origin. They are called shield volcanoes, formed as the giant Pacific plate moves slowly but steadily over a hot spot of magma from deep within the Earth.

A shield volcano is a wide volcano with shallowly-sloping sides. Shield volcanoes are formed by lava flows of low viscosity – lava that flows easily. The largest is Mauna Loa on the Big Island of Hawaii; all the volcanoes in the Hawaiian Islands are shield volcanoes. …

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.

Shield volcanoes are large volcanoes that are built almost entirely of fluid lava flows, and have broad sloping sides and are generally surrounded by gently sloping hills in a circular or fan-shaped pattern that looks like a warrior’s shield.

Its cherry-red lava flows and roaring lava fountains are impressive, especially when seen at night. But relatively few people have been killed by Kilauea’s lava, because it is usually possible for people to get out of its path. The one major fatality at Kilauea was caused by a steam explosion.

Supervolcanoes

• it erupts at least 1,000 km 3 of material (a large volcano erupts around 1 km 3)
• it forms a depression, called a caldera (a volcano forms a cone shape)
• a supervolcano often has a ridge of higher land around it.
• a supervolcano erupts less frequently – eruptions are hundreds of thousands of years apart.

Oruanui eruption

Helens is the volcano in the Cascades most likely to erupt again in our lifetimes. It is likely that the types, frequencies, and magnitudes of past activity will be repeated in the future.

Mount Mazama (Giiwas in the Native American language Klamath) is a complex volcano in the state of Oregon, United States, in a segment of the Cascade Volcanic Arc and Cascade Range. Most of the mountain collapsed following a major eruption approximately 7,700 years ago.

stratovolcanoes

The blue beauty of Crater Lake extends beyond its depth. Visitors can swim at designated areas, but beware — the water is usually very cold! The water of Crater Lake is a deep, gorgeous blue.

Mt Hood

The Legend The Aboriginal dream-time legend has it that three sisters, ‘Meehni’, ‘Wimlah’ and ‘Gunnedoo’ lived in the Jamison Valley as members of the Katoomba tribe. These beautiful young ladies had fallen in love with three brothers from the Nepean tribe, yet tribal law forbade them to marry.

10,363′