If you close your eyes and imagine a typical volcano, chances are you’re thinking of a cinder cone. In this lesson, you’ll find out how cinder cones grow, and learn about examples of this common landform.
A cinder cone, also called a scoria cone, is a volcano composed of volcanic cinders (scoria), or small, rough particles of hardened lava. When lava that is highly charged with gas bubbles erupts from a vent under pressure, it tends to shoot straight up into the air. This effect is called a fire fountain, and it can sometimes be hundreds of meters high.Blobs of the frothy lava break apart, cool quickly, and fall relatively close to the vent.
Over time, a cone-shaped hill builds up around a circular crater.
Cinder cones are the simplest and most common type of volcano. They can develop as free-standing volcanoes, but can also grow around new vents on the slopes of existing shield volcanoes or stratovolcanoes.Because the cinders that make up a cinder cone have already solidified by the time they hit the ground, the cone is just a pile of loose particles, pretty much like a sand dune – not cemented together by flowing lava.
However, because each cinder has rough, jagged edges, the particles tend to lock together, and the pile is relatively stable at the angle of repose, about 33 degrees. But it’s not strong enough or dense enough to support the quieter, ‘un-fizzy’ lava that emerges later in the eruption, so that lava often flows out under the base of the cinder cone and forms a smooth ‘pad’ for it to sit on.Cinder cones can grow quickly, but they don’t become giants. Big for a cinder cone is just a few hundred meters high.
But cinder cones often ‘piggyback’ on much larger volcanoes.Cinder cones are a ‘friendly face’ of volcanic activity – their fire-fountain eruptions are beautiful and dramatic, and because their lava tends to fall straight down and cool quickly, they don’t endanger thousands of lives or lay waste to vast areas. It can be relatively safe to view these eruptions close-up – of course, with any erupting volcano, ‘relatively’ is an important word.A cinder cone looks smooth and inviting to climb, and the view from the top can be great! But unless you stick to an established trail, make sure you have the right footwear. Scoria particles are glassy and sharp and will tear up your flip-flops in no time.
Sturdy hiking boots are best. Also, it’s smart to wear tough clothing that will give you some protection if you fall. A cinder cone may look a lot like a sand dune, but its harsh surface is no fun at all to roll down!
Paricutin, born in 1943, is probably the world’s most famous cinder cone. It started as a mysterious cloud of ash and small rocks in Dionisio Pulido’s cornfield in Michoacán state, Mexico. He and his wife were working there at the time but, fortunately, were able to get away. Over time, the volcano grew, attracting many curious visitors, including geologists. Although it eventually grew so large that the village had to be abandoned, the growth of the young volcano was slow enough that people had time to move away.
No one died from the eruption itself, although three people were struck and killed by lightning from an ash cloud. By the time it stopped erupting in 1952 – nine years later – Paricutin’s summit rose 424 meters above its original cornfield home.Wizard Island is a small cinder cone that has developed inside the crater of a much larger ancient volcano, which is known today as Crater Lake, in Oregon. The original volcano, called Mount Mazama, collapsed after a catastrophic eruption over 7,000 years ago, and small cinder cones began to grow within the caldera. However, it also began to fill with water, and today, Wizard Island is the only cone that rises above the surface of the lake.
Crater Lake and its surroundings are now a national park, and Wizard Island attracts thousands of tourists and hikers every year.
Cinder-cone volcanoes are volcanoes whose cones are composed of small, rough particles of solidified lava. The cone builds up over time from lava eruptions that shoot straight up, break apart, cool rapidly and fall near the vent they erupt from. They can grow as free-standing volcanoes or around new vents on the slopes of older, larger volcanoes.
The scoria, or cinders, that make up the cones are not cemented together but are interlocked by the roughness of their edges. Cinder-cone volcanoes tend to grow quickly, but not larger than a few hundred meters tall, and because their fire-fountain eruptions usually shoot straight up and cool quickly, they do much less damage than other types of volcanoes.
- Cinder cones are the simplest and most common type of volcano.
- Cinder cones form over time from particles from fire fountains.
- Cinder cones are never huge and have a slope of around 33 degrees.
- They can be new volcanoes, or they can form over the vents of pre-existing volcanoes.
The act of studying this lesson on cinder cone volcanoes could prepare you to achieve these objectives:
- Discuss the creation of cinder cones
- List some related characteristics and facts
- Name two real cinder cone volcanoes