A cinder cone volcano, also known as a pyroclastic cone or scoria cone, is a volcano with a simple, steep-sided conical shape consisting of cinders and other volcanic debris from an explosive eruption. Despite their relatively small size compared to other types of volcanoes, cinder cones play a significant role in the landscape and provide insights into volcanic activity.
What Is a Cinder Cone Volcano?
A cinder cone volcano is a steep, conical hill made of volcanic ash, cinders, and other pyroclastic materials ejected during explosive eruptions. These materials include fragments of lava that cool and solidify quickly. The debris accumulates around the volcanic vent, creating a distinct cone shape.
Why Is it Called a “Cinder Cone”?
The name “cinder cone” comes from the type of material that primarily composes these volcanoes—cinders. Cinders are small, rough fragments of lava typically less than an inch in diameter, ejected into the air during volcanic eruptions.
Key Features of Cinder Cone Volcanoes
- Steep Slopes: Cinder cones have steep slopes, often between 30-40 degrees. The slopes are steep due to the loose, fragmented nature of the material that makes up the cone. Often, the cone is symmetrical unless wind redistributes the ejected material.
- Short and Small: Cinder cones are usually small, typically ranging from tens to hundreds of meters in height.
- Summit Crater: A prominent crater often sits at the summit, formed from the explosive ejection of material.
- Loose Pyroclastic Material: The cone consists of pyroclastic debris, including ash, lapilli (small stones), and volcanic bombs. The material consists of basaltic to andesitic pyroclastic material.
- Short Eruption Lifespan: Cinder cones typically erupt for a short period, often in a single episode that can last from days to a few years.
Structure of Cinder Cone Volcanoes
Cinder cone volcanoes have a relatively simple structure compared to other types of volcanoes:
- Crater: A crater is a bowl-shaped depression at the summit, formed by explosive eruptions.
- Volcanic Vent: A vent is an opening at the ground surface where magma erupts. In addition to the main crater, some cinder cones have one or more additional vents.
- Cone: This is the main body of the volcano, formed from accumulated cinders and ash.
- Layers of Ash and Cinders: The cone consists of alternating layers of volcanic ash, cinders, and occasionally lava flows.
Formation and Life Cycle of a Cinder Cone Volcano
Cinder cones form when gas-charged lava violently ejects from a vent, breaking into small fragments that cool and solidify as they fall back to the ground. The formation process includes:
- Initial Eruption: Gas-rich magma rises to the surface, fragmenting as it escapes, creating ash and cinders.
- Cone Building: Pyroclastic material accumulates around the vent, building the cone structure.
- Crater Formation: Continued explosive activity creates a crater at the summit.
- Lava Flow (Optional): Lava may breach the cone, flowing out to form surrounding lava fields.
Sometimes cinder cones form on their own, directly above a small, shallow magma source. For example, Parícutin formed unexpectedly in a farmer’s field in 1943. However, the cones commonly form in connection with other volcanoes.
- Shield Volcanoes: Cinder cones frequently appear on shield volcanoes, such as those in Hawaii and on Mars. They dot the flanks of the larger shield volcano.
- Stratovolcanoes: Stratovolcanoes, known for their alternating explosive and effusive eruptions, sometimes have cinder cones on their slopes. These smaller cones form as a result of minor eruptions that occur away from the main summit vent. For example, Mount Etna in Italy has several cinder cones on its flanks.
Do Cinder Cones Produce Lava?
Cinder cone eruptions are characterized by explosive activity rather than continuous lava flow. Most of the time, these eruptions do not release lava. However, lava occasionally breaches the cone or erupts from the base. These flows are usually basaltic, making them fluid and capable of traveling significant distances.
Where Do Cinder Cones Form?
Cinder cones occur worldwide, often near or on larger volcanoes, rift zones, or volcanic fields. Common locations include:
- Western United States: Craters of the Moon, Sunset Crater.
- Mexico: Parícutin.
- Iceland: Hverfjall.
- Africa: Mount Kilimanjaro’s Shira cone.
- Pacific Islands: Numerous examples across the Hawaiian islands.
Specific examples of cinder cones are:
- Parícutin, Mexico – Grew rapidly in 1943 and erupted for nine years.
- Sunset Crater, Arizona, USA – Erupted around 1085 AD.
- Lava Butte, Oregon, USA – Part of Newberry National Volcanic Monument.
- Cinder Cone, Lassen Volcanic Park, USA – Known for its vibrant red color.
- Eldfell, Iceland – Formed in 1973 on Heimaey Island.
- Capulin Volcano, New Mexico, USA – A classic cinder cone with a well-preserved crater.
- Hverfjall, Iceland – A large cinder cone near Lake Mývatn.
- Mauna Kea Cinder Cones, Hawaii, USA – Various cinder cones dot the landscape.
- Izalco, El Salvador – Once known as the “Lighthouse of the Pacific.”
- Mount Etna Cinder Cones, Italy – Several smaller cones flank this stratovolcano.
Cinder Cones on Other Planets
There are cinder cones on other planets and moons, such as Mars and the Moon. These features suggest past volcanic activity similar to Earth’s.
Are Cinder Cones Dangerous?
Cinder cones are generally less hazardous compared to larger volcanoes, but they still pose risks such as:
- Lava Flows: Potentially destroy property and alter landscapes.
- Ash Fall: Impacts air quality, machinery, and agriculture.
- Explosive Eruptions: Pose risks to nearby populations due to pyroclastic material.
Frequently Asked Questions (FAQs)
- How long do cinder cone eruptions last?
Typically from days to a few years. - Can cinder cones erupt multiple times?
Usually, they erupt once, but some cones have multiple eruptive episodes. - Do cinder cones produce lava?
Some do, although lava production is often secondary to explosive eruptions. - Why are cinder cones small compared to other volcanoes?
They form from smaller, localized eruptions that do not sustain long-term activity. - Are cinder cones found underwater?
Yes, they form underwater near volcanic islands and seafloor rift zones. - What happens to a cinder cone after it erupts?
It gradually erodes over time unless new eruptions occur. - Can cinder cones trigger larger volcanic eruptions?
Typically no, as they are usually not connected to larger magma chambers. - What materials occur in cinder cones?
Primarily basaltic cinders, ash, and volcanic bombs. - Are cinder cones active today?
Some, like Parícutin, have erupted in recent history, but many are dormant. - Do cinder cones pose a threat to aviation?
Ash from cinder cone eruptions can be hazardous to aircraft.
References
- Bleacher, J.E.; Greeley, R.; Williams, D.A.; Cave, S.R.; Neukum, G. (2007). “Trends in effusive style at the Tharsis Montes, Mars, and implications for the development of the Tharsis province”. J. Geophys. Res. 112 (E9): E09005. doi:10.1029/2006JE002873
- Clarke, Hilary; Troll, Valentin R.; Carracedo, Juan Carlos (2009). “Phreatomagmatic to Strombolian eruptive activity of basaltic cinder cones: Montaña Los Erales, Tenerife, Canary Islands”. Journal of Volcanology and Geothermal Research. doi:10.1016/j.jvolgeores.2008.11.014
- Fisher, R.V.; Schmincke, H.-U. (1984). Pyroclastic Rocks. Berlin: Springer-Verlag. ISBN 3540127569.
- Schmincke, Hans-Ulrich (2003). Volcanism. Berlin: Springer. ISBN 978-3-540-43650-8.
- Wood, C.A. (1979). “Cinder cones on Earth, Moon, and Mars“. Lunar Planet. Sci. Vol. X. pp. 1370–72.