Download This Sample
This sample is exclusively for KidsKonnect members!
To download this worksheet, click the button below to signup for free (it only takes a minute) and you'll be brought right back to this page to start the download!
Sign Me Up
A volcano is a gap in the crust of a planet, such as Earth, that permits hot lava, volcanic ash, and gases to flow from a magma chamber under the surface. Volcanoes are the geologic builders of the Earth. They have generated more than 80% of our planet’s surface, establishing the groundwork for life to thrive. Their explosive energy creates mountains and craters, and lava rivers flow over desolate terrain. However, as time passes, the elements break down these volcanic rocks, freeing nutrients from their stony prisons and resulting in astonishingly rich soils that have allowed civilizations to thrive.
See the fact file below for more information about Volcano, or download the comprehensive worksheet pack, which contains over 11 worksheets and can be used in the classroom or homeschooling environment.
Key Facts & Information
- The term volcano is taken from the name Vulcano, a volcanic island in Italy‘s Aeolian Islands, whose name is derived from Vulcan, the Roman god of fire.
- Volcanology, sometimes written vulcanology, is the study of volcanoes.
- The Earth’s lithosphere, its solid outer shell, is divided into sixteen main and many smaller plates, according to plate tectonics theory.
- These are moving owing to convection slowly in the underlying ductile mantle. Most volcanic activity on Earth occurs around plate boundaries, where plates are converging (destroying the lithosphere) or diverging (and a new lithosphere is being created).
DIVERGENT PLATE BOUNDARIES
- Two tectonic plates separate at the mid-ocean ridges as heated mantle rock moves higher beneath the thinning oceanic crust. The drop in pressure in the ascending mantle rock causes adiabatic expansion and partial melting, resulting in volcanism and forming a new oceanic crust.
- Because most divergent plate borders are at the ocean’s bottom, most volcanic activity on Earth occurs underseas, generating new seabeds. This type of volcanic activity is evidenced by black smokers (also known as deep sea vents). Volcanic islands, such as Iceland, arise where the mid-oceanic ridge rises above sea level.
CONVERGENT PLATE BOUNDARIES
- Subduction zones are where two plates clash: an oceanic plate and a continental plate. The marine plate subducts (dives below the continental plate), forming a deep ocean trench immediately offshore.
- Water discharged from the subducting plate reduces the melting point of the overlying mantle wedge, resulting in magma formation.
- Because of its high silica concentration, this lava is highly viscous and seldom reaches the surface, cooling and solidifying deep. When it gets to the surface, it creates a volcano.
- Volcanic arcs, chains of volcanoes thus bound subduction zones. Volcanoes in the Pacific Ring of Fire, including the Cascade Volcanoes of the Japanese Archipelago, or the Sunda Arc of Indonesia, are typical examples.
- Hotspots are volcanic zones created by mantle plumes, considered hot material columns emerging from the core-mantle boundary. As with mid-ocean ridges, rising mantle rock undergoes decompression melting, resulting in vast amounts of magma.
- A continent’s interior can experience sustained upwelling of heated mantle rock, which can result in rifting. Flood basalts describe the early phases of rifting, which can continue to the point where a tectonic plate is separated.
- A diverging plate boundary forms between the two parts of the split plate. However, rifting frequently fails to completely break the continental lithosphere (as in an aulacogen), and unsuccessful rifts are distinguished by volcanoes erupting peculiar alkali lava or carbonatites. The East African Rift Valley volcanoes are one example.
- Most of the world’s volcanoes develop near the borders of Earth’s tectonic plates, which are vast expanses of our planet’s lithosphere that constantly move and collide. When two tectonic plates meet, one frequently sinks deep beneath the other, creating a subduction zone.
- Temperatures and pressure rise as the descending continent descend further into the Earth, releasing water from the rocks. The water slightly lowers the melting point of the surrounding rock, resulting in magma that can rise to the surface and reactivate a dormant volcano.
- However, not all volcanoes are associated with subduction. Hotspot volcanism is another method through which volcanoes can originate. In this case, a hotspot of magmatic activity in the center of a tectonic plate can force up through the crust and produce a volcano.
- Although the hotspot is assumed to be primarily immobile, the tectonic plates continue their slow march, forming a line of volcanoes or islands on the surface. This mechanism is considered to be hidden behind the volcanic chain of Hawaii.
- The most familiar image of a volcano is of a conical mountain spouting lava and deadly fumes from its top crater; however, this only depicts one of the various forms of volcanoes.
- Volcanoes have significantly more sophisticated characteristics, and multiple causes determine their structure and behavior.
- Volcanic fissure vents are horizontal, linear cracks through which lava flows.
- Shield volcanoes are generated by the eruption of low-viscosity lava that may flow for a long distance from a vent. They are distinguished by comparatively mild effusive eruptions rather than cataclysmic explosions.
- Shield volcanoes are more prevalent in marine than continental settings because low-viscosity magma is often low in silica. The Hawaiian volcanic chain comprises shield cones, which are also frequent in Iceland.
- Slow eruptions of exceedingly viscous lava form lava domes. They can form inside the crater of a prior volcanic eruption, like with Mount St. Helens, or they can develop independently, as with Lassen Peak.
- They can generate intense, explosive eruptions like stratovolcanoes, although the lava usually does not flow far from the generating vent.
- When viscous lava is driven upward, forcing the surface to expand, cryptodomes occur.
- Mount St. Helens’ 1980 eruption was an example; lava under the mountain’s top generated an upward bulge, eventually tumbling down the mountain’s north side.
- Cinder cones are formed by accumulating minute fragments of scoria and pyroclastics (both resemble cinders, thus the name of this volcanic type).
- These short-lived eruptions can build a cone-shaped mound 30 to 400 meters (100 to 1,300 feet) tall. Most cinder cones explode just once, and cinder cones can arise as flank eruptions on more enormous volcanoes or independently.
- Cinder cones are Paricutin in Mexico and Sunset Crater in Arizona. Caja del Rio is a volcanic region in New Mexico with approximately 60 cinder cones.
- Based on satellite pictures, it proposed that cinder cones might exist on the surfaces of other terrestrial worlds in the Solar System, including Mars and the Moon.
STRATOVOLCANOES (COMPOSITE VOLCANOES)
- Stratovolcanoes or composite volcanoes are towering conical mountains made up of lava flows and tephra in alternating layers, thus the name.
- They are sometimes directed to composite volcanoes since they are formed from many structures during various eruptions.
- Mount Fuji in Japan, Mayon Volcano in the Philippines, and Mount Vesuvius and Stromboli in Italy are all classic examples.
- A supervolcano is a volcano that has erupted with more than 1,000 cubic kilometers (240 cubic miles) of volcanic deposits in a significant explosive event.
- A massive magma chamber filled with gas-rich, silicic magma is emptied in a catastrophic caldera-forming eruption. The only volcanic product with quantities comparable to flood basalts is ash flow tuffs deposited by such explosions.
- A supervolcano may wreak havoc on a continental scale. Because of the massive amounts of sulfur and ash spewed into the atmosphere, such volcanoes can significantly reduce global temperatures for several years following the eruption. They are the most deadly volcanoes.
- Some examples are Yellowstone Caldera in Yellowstone National Park and Valles Caldera in New Mexico (both located in the western United States).
- Supervolcano eruptions are, fortunately, highly unusual phenomena; yet, due to the vast area they cover and subsequent hiding under flora and glacial deposits, supervolcanoes can be challenging to spot in the geologic record without thorough geologic mapping.
- Submarine volcanoes are typical ocean bottom landforms. Volcanic activity at just 119 undersea volcanoes has been reported throughout the Holocene Epoch. However, there may be more than one million geologically young submarine volcanoes on the seabed.
- Active volcanoes in shallow water reveal their presence by erupting steam and rocky debris far above the ocean’s surface. The immense weight of the water in deep ocean basins prohibits the explosive discharge of smoke and gases, yet, undersea eruptions can be discovered by hydrophones and by the coloring of water caused by volcanic gases.
- Pillow lava is a frequent eruptive result of underwater volcanoes, and it is distinguished by thick sequences of irregular pillow-shaped volumes that develop beneath the ocean.
- Subglacial volcanoes form beneath icecaps. It is composed of lava plateaus that cover extensive pillow lavas and palagonite. Iceland and British Columbia have excellent examples of this type of volcano.
- Mud volcanoes (mud domes) are landforms formed by geo-excreted gases and liquids, albeit various mechanisms can cause such activity.
- The most significant constructions have a diameter of 10 kilometers and a height of 700 meters.
TYPES OF VOLCANIC ERUPTIONS
- There are three types of eruptions: magmatic, phreatomagmatic, and phreatic.
- Gas release from decompression drives magmatic eruptions. Low-viscosity magma with little dissolved gas creates very moderate effusive eruptions.
- High-viscosity magma with a high amount of liquefied gas creates powerful explosive eruptions. Historical examples are used to demonstrate the spectrum of observed eruption styles.
- The interplay of rising magma with groundwater characterizes phreatomagmatic eruptions. They are propelled by the ensuing fast pressure rise in the superheated groundwater.
- Superheating of groundwater in contact with hot rock or magma characterizes phreatic eruptions. They are distinguishable from phreatomagmatic eruptions by the absence of magma in the erupted material.
- Volcanoes vary widely in their degree of activity, with particular volcanic systems seeing eruptions multiple times a year to once per tens of thousands of years.
- Volcanoes are unofficially classified as erupting, active, dormant, or extinct, but definitions of these categories vary among volcanologists. Most volcanoes’ levels of activity lie on a graded scale, with substantial overlap between categories, and do not usually fit cleanly into simply one of these three distinct groups.
- The USGS classifies a volcano as “erupting” when magma ejection from any location on the volcano is observable, including visible magma still confined within the top crater walls.
- While there is no universal agreement among volcanologists on defining an “active” volcano, the USGS considers a volcano to be “active” when subsurface indications such as earthquake swarms, ground inflation, or abnormally high amounts of carbon dioxide and sulfur dioxide are evident.
DORMANT AND REACTIVATED
- The USGS defines a “dormant volcano” as any volcano that is not displaying indicators of disturbance, such as earthquake swarms, ground swelling, or significant noxious gas emissions but does show evidence that it might become active again.
- Many dormant volcanoes have not erupted in thousands of years, yet there are clues that they may erupt again in the future.
- Extinct volcanoes are ones that experts believe are unlikely to erupt again due to a lack of magma supply. Many volcanoes on the Hawaiian-Emperor seamount chain in the Pacific Ocean (even though some volcanoes at the eastern end of the thread are active), Hohentwiel in Germany, Shiprock in New Mexico, U.S., Capulin in New Mexico, US, Zuidwal volcano in the Netherlands, and several volcanoes in Italy, such as Monte Vulture, are examples of extinct volcanoes.
- It is frequently challenging to verify whether a volcano is genuinely extinct. Because “supervolcano” calderas can have eruptive lifespans estimated in the millions of years, a caldera that has not erupted in thousands of years may be deemed dormant rather than extinct.
- Aside from lava flows, volcanic eruptions offer several hazards. During active outbreaks, it is critical to follow local authorities’ recommendations and evacuate areas as needed.
- Pyroclastic flows, avalanches of hot rocks, ash, and poisonous gas that rush down slopes at rates of up to 450 miles per hour are one specific risk.
- After Mount Vesuvius erupted in BCE 79, such an event wiped away the population of Pompeii and Herculaneum.
- Similarly, volcanic mudflows known as lahars may be highly devastating. These fast-moving mud and debris surges may bury entire communities as they speed down a volcano’s sides.
- Another volcanic hazard is ash. Unlike the soft, fluffy particles of burned wood left over from a bonfire, volcanic ash comprises jagged shards, boulders, and volcanic glass, each smaller than two millimeters across. As the gasses within the rising magma expand, breaking the cooling rocks as they burst from the volcano’s mouth, ash develops.
- It’s not just hazardous to inhale; it’s also heavy and accumulates rapidly. Volcanic ash may collapse vulnerable structures, create power outages, and be difficult to remove after an eruption.
- Although volcanic explosions pose significant risks to people, previous volcanic activity has generated substantial economic resources.
- Volcanic ash and weathered basalt provide some of the world’s most fertile soil, rich in nutrients including iron, magnesium, potassium, calcium, and phosphorus.
- Tuff is a relatively soft rock created from volcanic ash that has been utilized for building since prehistoric times. Tuff, plentiful throughout Italy, was frequently used for construction by the Romans. The Rapa Nui people built most of the moai figures on Easter Island out of tuff.
- Volcanic activity is to blame for displacing essential mineral resources such as metal ores. High heat transfer rates from the Earth’s core accompany volcanic activity. These can be used to generate geothermal energy.
- Many volcanoes close to human settlements are closely monitored to provide enough prior notice of impending eruptions to neighboring people. Furthermore, a greater modern understanding of volcanology has resulted in some more educated governmental reactions to unexpected volcanic activity.
- While the science of volcanology may not yet be able to foresee the exact times and dates of future eruptions, monitoring ongoing volcanic indicators on suitably monitored volcanoes is generally capable of predicting impending eruptions with warnings as few as hours and as many as days before any imminent eruptions.
- While volcanic eruptions may still inflict considerable property damage in many circumstances, the recurring large-scale loss of human life that was formerly linked with many volcanic eruptions has lately been significantly decreased in locations where volcanoes are effectively monitored.
- This life-saving capability is derived from volcanic-activity monitoring programs, enhanced local officials’ capacity to enable prompt evacuations based on modern-day volcanism knowledge, and improved communications technology such as mobile phones.
This bundle contains 11 ready-to-use Volcano Worksheets that are perfect for students who want to learn more about Volcano, which is a gap in the crust of a planet such as Earth that permits hot lava, volcanic ash, and gases to flow from a magma chamber under the surface.
Download includes the following worksheets:
- Volcano Facts
- The Biggest of Them All
- Volcano Timeline
- Cinder Cones – Cinder Match
- Composite Volcanoes – Stratovolcano Coloring
- Locale Stratovolcano
- Shield Volcanoes
- The Ring of Fire
- Active Volcanoes – Ready Anytime
- Big Bangs – Erupting Scales
- Key Answers
Frequently Asked Questions
What is a volcano?
A volcano is a gap in the crust of a planet, such as Earth, that permits hot lava, volcanic ash, and gases to flow from a magma chamber under the surface.
What is plate tectonics?
These are moving owing to convection slowly in the underlying ductile mantle. Most volcanic activity on Earth occurs around plate boundaries, where plates are converging (destroying the lithosphere) or diverging (and new lithosphere is being created).
What happens if a supervolcano erupts?
A supervolcano may wreak havoc on a continental scale. Because of the massive amounts of sulfur and ash spewed into the atmosphere, such volcanoes can significantly reduce global temperatures for several years following the eruption. They are the most deadly volcanoes.
What are some dangers of volcanoes?
Pyroclastic flows, avalanches of hot rocks, ash, and poisonous gas that rush down slopes at rates of up to 450 miles per hour are one specific risk.
Can we predict volcanic eruption?
While the science of volcanology may not yet be able to foresee the exact times and dates of future eruptions, monitoring ongoing volcanic indicators on suitably monitored volcanoes is generally capable of predicting impending eruptions with warnings as few as hours and as many as days before any imminent eruptions.
Link/cite this page
If you reference any of the content on this page on your own website, please use the code below to cite this page as the original source.
Link will appear as Volcano Facts & Worksheets: https://kidskonnect.com - KidsKonnect, November 15, 2017
Use With Any Curriculum
These worksheets have been specifically designed for use with any international curriculum. You can use these worksheets as-is, or edit them using Google Slides to make them more specific to your own student ability levels and curriculum standards.