Volcanoes

There are many active volcanoes in Arizona

A volcano is an opening in Earth’s surface through which magma, ash, and gas can escape. Volcanoes form when magma rises up from deep within the Earth and collects in magma chambers near the surface. When pressure in the magma chamber becomes too great, the magma is forced out through the opening at the top of the volcano.

The main parts of a volcano are:

1. The magma chamber: This is a reservoir of molten rock located deep beneath the Earth’s surface.

2. The vent: This is the opening at the top of the volcano through which magma, ash, and gas are expelled.

3. The crater: This is a depression at the top of the volcano surrounding the vent. It is created by the explosive eruption of ash and rocks.

4. The slope: This is the sides of the volcano, which can be steep or gentle depending on the type of volcano.

5. The lava flows: These are rivers of molten rock that flow down the slopes of the volcano.

6. The ash deposits: These are layers of fine, powdery ash that are expelled during an eruption and settle to the ground.

7. The pyroclastic flows: These are fast-moving clouds of ash, gas, and rocks that can travel down the slopes of the volcano at high speeds.

8. The lava dome: This is a mound of lava that forms around the vent of a volcano during an eruption.

There are several different types of volcanoes, including:

1. Shield volcanoes: These are wide, gentle slopes with a shape resembling a warrior’s shield. They are formed by relatively fluid lava flows that spread out over a wide area.

2. Cinder cone volcanoes: These are steep, conical hills with a circular base. They are formed by explosive eruptions that spew out ash, cinders, and other pyroclastic material.

3. Composite volcanoes: These are also known as stratovolcanoes. They have a conical shape and are composed of alternating layers of lava flows and pyroclastic material. They are formed by both explosive eruptions and effusive lava flows.

4. Lava dome volcanoes: These are small, dome-shaped volcanoes formed by the slow extrusion of viscous lava.

5. Submarine volcanoes: These are volcanoes that form under the ocean. They can be any of the above types, but are most commonly shield volcanoes.

6. Cryovolcanoes: These are volcanoes that erupt with volatiles like water, ammonia, or methane rather than magma. They are found on planets and moons with volatile-rich surfaces, such as Saturn’s moon Enceladus.

Map of the Volcanoes on Pinal County

There are a lot of volcanoes in Arizona, including:

1. Sunset Crater: This is a cinder cone volcano located in the San Francisco Volcanic Field in northern Arizona. It was formed about 900 years ago and is the youngest volcano in the field.

2. San Francisco Peaks: These are a group of peaks located in the San Francisco Volcanic Field near Flagstaff. The range is the remnant of San Francisco Mountain The highest peak, Humphreys Peak, is the highest point in Arizona at 12,633 feet (3,851 meters). The whole San Francisco field includes around 600 volcanoes.

3. Bill Williams Mountain: This is a lava dome volcano located in the San Francisco Peaks Range near Flagstaff in northern Arizona. It last erupted about 1.4 million years ago.

4. Mojave Mountain: This is a stratovolcano located in the Hualapai Mountains, Mohave County in western Arizona. It last erupted about 2 million years ago.

5. Cerbat Mountains: These are a group of stratovolcanoes located in Mohave County, northwest Arizona. They last erupted about 25 million years ago.