VOLCANO COMPARISON

STRATOVOLCANO

WHERE

• Some famous stratovolcanoes include...
• Mt St Helens in Skamania County, Washington
• Mt Vesuvius in the Gulf of Naples, Italy
• Mt Fuji on Honshu Island, Japan

Judging from these locations, stratovolcanoes are mostly in the Ring of Fire, where most natural disasters occur. Areas like Italy, Japan or the west coast of the US (all of which are areas in the Ring of Fire) are often hit with natural disasters such as earthquakes, so volcanoes wouldn't be out of place in these locations. In terms of plate tectonics, stratovolcanoes are typically found on convergent boundaries, but there have been some stratovolcanoes that have formed on subduction zones.

Size & Shape
These volcanoes often range from as low as 2,000 feet to as high as 22,000 feet! That's nearly four and a half miles into the air! The volcanoes themselves are very tall and steep in a cone shape, like the ones in cartoons or the ones you would make for a science project.

What It's Made Of
A Stratovolcano is composed of one layer of hardened lava, tephra, and volcanic ash.

Eruption Characteristics
Aside from the very tall and steep shape, one thing that most people associate with stratovolcanoes is their very explosive eruptions. Stratovolcanoes don't do "quiet." Their lava is highly viscous, but cools and hardens before it can spread too far. When it comes to ash, one of the materials that make up a Stratovolcano is ash, so some of it is going to be released. Pyroclastic flows are a mixture of semi-solid fragments and hot, toxic, expanding gasses that moves similar to an avalanche. Mt St Helens is a good example of an eruption with pyroclastic flow.

Damage
The ash and smoke rising into the air can make it difficult and dangerous to breathe. Since the lava cools and hardens shortly after being released, the land around the volcano is destroyed and replaced with hardened lava. The climate becomes very warm. Some stratovolcanoes have even been said to cause tsunamis! Stratovolcanoes often have a crater at the summit.

FAMOUS VOLCANO

FAMOUS VOLCANO

FAMOUS VOLCANO

CINDER CONE

WHERE

• Some famous cinder cone volcanoes include...
• Lava Butte in Bend, Oregon
• Volcán de Parícutín in Michoacán, Mexico
• Mount Etna in Sicily, Italy

Same as the stratovolcanoes, cinder cone volcanoes are mostly in the Ring of Fire. In terms of plate tectonics, these volcanoes are mostly found on divergent plate boundaries.

Size & Shape
Cinder cone volcanoes are usually pretty short, 250 meters to 650 meters in height, and typically about 500 meters in diameter. They look, well, like a cone! They look like a much smaller Stratovolcano, with a much more rounded shape. They have a bowl shaped crater at the summit.

What It's Made Of
Cinder cone volcanoes are made of basaltic fragments, as well as ash, cinders, and bombs (melted volcanic rock).

Eruption Characteristics
While not nearly as sudden or explosive as the previously mentioned stratovolcanoes, cinder cones still have a unique and interesting eruption. The volcano loses most of its gas before the actual eruption, so the runny magma slowly oozes out from the crater as lava. It is rarely released from the top (except when in the form of a fountain) because the cone is often too weak to support it. So I would say the eruption is much more quiet than explosive. Once again, since the volcano is literally composed partially of ash, some will be released in the process of eruption.

Damage
Cinder cone volcanoes honestly don't do much damage. So blobs of lava may be released, but those will cool off at nearly the same time they hit the air. But the smoke and ash may cause damage when breathing. These lava blobs , when hardened, add to the shape of the volcano. Along with the blobs, some of the bombs that make up the volcano are also released. Lakes can be formed from the craters, and islands can be formed from the cinder cone volcanoes in the water. They do not erode because they can absorb the water. The volcanic ash and gas are ejected into the upper atmosphere and can block out the sunlight. This will not allow sunlight through, so nothing can get sunlight and things will be cooler.

FAMOUS VOLCANO

FAMOUS VOLCANO

FAMOUS VOLCANO

SHIELD

WHERE

• Some famous shield volcanoes include...
• Mauna Loa on Hawaii's Big Island
• Mauna Kea on Hawaii's Big Island
• Kilauea on Hawaii's Big Island

Shield volcanoes are unique in the way that they aren't usually found near one specific plate boundary. They are actually known to be found on hotspots.

Size & Shape
The shield volcano is the smallest of the three volcano types that I have mentioned, only reaching from about 1,500 to 2,000 feet. It is shaped like a warrior's shield lying on the ground. The crater has a sloping cone shape.

What It's Made Of
Shield volcanoes are made of built up lava that flows easily.

Eruption Characteristics
Being the calmest of the three, shield volcanoes are obviously more quiet than explosive, as they slowly build up over time. They have very slow-moving and fluid lava, and probably the least amount of ash out of these three.

Damage
Without the ash or pyroclastic flow of the previous two, the shield volcano doesn't do much damage to the air. Since the lava is very fluid, it is able to spread over large areas. That causes a lot of damage to the land, as well as the plants and animals. The destroyed land is ultimately replaced by black, hardened lava. Interactions with the water may cause some eruptions to become hydrovolcanic. They are basically the wet equivalents of "Strombolian" eruptions. With not much dust and not much ash, the volcanoes hardly make any changes to the climate, and in fact may make it warmer.

FAMOUS VOLCANO

FAMOUS VOLCANO

FAMOUS VOLCANO

THE END