Cinder cone volcanoes are volcanoes which are typically characterized by highly steep slopes, and a bowl-shaped crater at the top. These are the most common volcanic structures on the planet, such that if you are to picture a volcano, the chances that you will end up picturing a cinder cone volcano exist in plenty. Simply put, these are cinder cones or scoria cones, i.e. steep conical hills, formed by accumulation of volcanic fragments around the single vent. As these vents continue to erupt even after these conical structures are formed around them, they are referred to as cinder cone volcanoes.
Cinder cones are most often associated with Strombolian eruptions, which are relatively low-level volcanic eruptions that range from small to medium in terms of volume. These eruptions consist of incandescent cinders, lapilli and lava bombs. In fact, the cinders - from which these volcanic structures get their name, are pebble-like glassy structures with air bubbles within that are formed when magma explodes in air, and cools in mid-air before it comes to the ground. These cinders get accumulated around the single vents wherein the first eruption takes place, and their piling in course of time results in formation of cinder cones.
As eruption continues, more and more lava is added to the volcanic structure and the cone can eventually attain a height of somewhere between 250 - 300 meters. However, there do exist cases wherein such cinder cones exceed the seemingly impossible height of 400 meters. Paricutin cinder cone volcano in the state of Michoacan in Mexico is one of the best examples of this. It erupted in a corn field for the first time in 1943, and continued to erupt for the period of next nine years as a result of which the structure attained a height of 424 meters.
As the vent walls - which are formed as a result of cinder accumulation, are not strong enough to contribute to the pressure created by molten rock, you seldom get to see eruption of such volcanoes from the top. In such circumstances, lava flow results in a breach on one side of the crater thus making it appear as if it were an amphitheater. Similarly, small eruptions from the flanks are also observed in some cases. Furthermore, when the gas pressure drops further, lava flow can also break through the base of the volcanic structure. Such eruptions can also alter the shape of a volcano, and eventually result in formation of aligned twin cones.
Interesting Facts about these Volcanoes
The volcanologists at the United States Geological Survey (USGS) state that cinder cones typically develop alongside other volcanoes, and that explains why they are often associated with shield volcanoes or calderas at times. There are as many as 100 cinder cones along the periphery of the famous Hawaiian shield volcano Mauna Kea.
Similarly, there exist as many as 300 cinder cones along the flanks of Mt. Etna volcano in Italy. With their average height ranging between 300 - 400 meters, these volcanoes are the smallest among the different types of volcanoes on the Earth. However, the fact that they grow quite rapidly as compared to their counterparts is also worth taking a note of.
The 'Cinder Cone and the Fantastic Lava Beds' at the Lassen Volcanic National Park in California are quite popular among hiking enthusiasts with its nature trail allowing hikers to go right up to its crater. Other popular cinder cone volcanoes in the United States of America include Mount Gordon in Alaska, Puu Oo in Hawaii, Mount Tabor in Oregon, the one located at the center of the Crater Lake in Oregon, etc. The Cerro Negro volcano in Nicaragua boasts of being the most active cinder cone volcano on the planet with as many as 23 eruptions since it came into existence in 1850.
With those cinder cone volcano facts, we covered a significant bit of information on these volcanic structures. Even though they are considered relatively harmless, that doesn't mean they cannot harm human life and property. Even these volcanoes emit harmful gases - such as carbon dioxide and sulfur dioxide, which can result in fatalities in high concentration. Similarly, there also exist instances of cinder cone lava engulfing vast stretches of land in the vicinity. The Paricutin cinder cone volcano is again an apt example here as the lava flow from it (during the 9 yearlong eruption) engulfed 9.7 sq miles of land around it.