The Ice Volcanoes on the Great Lakes
How They Form and Why They Matter
Ice volcanoes are mounds of ice that form along the shores of the Great Lakes when freezing temperatures and wave action combine, producing dramatic cone-like structures that spout water and slush through their tops. These features appear most often in winter and add a unique, dynamic element to the vast frozen landscape.
This natural phenomenon attracts curiosity from locals, scientists, and visitors alike. Every year, images and videos of ice volcanoes erupting with icy spray along Lake Michigan and Lake Superior circulate online, drawing attention to the striking and sometimes unexpected beauty found in the region.
Understanding how and why ice volcanoes form highlights the powerful interactions between cold air, open water, and wind that shape the Great Lakes during winter. For those interested in the natural world or looking for a reason to brave the cold, ice volcanoes provide a fascinating glimpse into the complex processes at work on some of North America’s largest lakes.
What Are Ice Volcanoes?
Ice volcanoes are temporary geological formations found along the shores of large, partially frozen lakes, especially the Great Lakes. They form unique cone-shaped structures built from ice and slush, driven by wave and wind action under cold weather conditions.
Defining Ice Volcanoes
Ice volcanoes are cone-shaped mounds of ice that form along shorelines where cold temperatures cause lake surfaces to freeze, but wave action keeps some water beneath the ice in motion. When strong waves push water and slush up through cracks or thin ice near the shore, the mixture erupts and accumulates, creating icy cones resembling miniature volcanoes.
Unlike true geological volcanoes, ice volcanoes do not involve lava or magma. Instead, their eruptions are made of water and slush forced up by wave energy. These features are seasonal and can appear and disappear within days or weeks, depending on weather conditions.
Ice volcanoes are most commonly seen on the Great Lakes during late winter, when cold air and persistent winds coincide. They can range from under a meter to several meters in height.
Ice Cone Formation
The formation process begins when air temperatures are low enough to freeze the surface layer of lake water near the shore. Persistent waves break apart this ice, creating small cracks and openings while pushing unfrozen water underneath. As wind and waves continue to force water through these holes, it splashes upward and immediately freezes, slowly building up a cone-shaped mound of ice.
This repeated process makes each eruption add a new layer of ice to the cone, similar to how layers form in traditional volcanic cones, but with frozen water instead of rock. Wind direction, wave strength, and surrounding air temperatures all influence how large and quickly these cones grow.
Ice cones often appear in clusters, sometimes stretching for hundreds of meters along the shoreline. Their shape and stability depend on the balance between ongoing wave action and freezing temperatures.
Key Differences from Regular Volcanoes
Ice volcanoes and regular volcanoes share a visual similarity in shape, but differ greatly in origin and behavior. Regular volcanoes are geological features formed by molten rock (magma) traveling from beneath the Earth's crust, which erupts as lava and ash.
In contrast, ice volcanoes are purely a surface phenomenon, requiring no magma or internal heat source. They result from water, wind, and cold air working together, with eruptions powered by wave pressure rather than tectonic or volcanic activity.
The lifespan of an ice volcano is also much shorter. While volcanic cones may last for thousands or millions of years, ice volcanoes persist only as long as freezing temperatures and active wave conditions are present, often disappearing completely as temperatures rise in spring.
Formation Process of Ice Volcanoes
Ice volcanoes on the Great Lakes are shaped by a combination of strong wave action, subfreezing air, and the gradual buildup of ice shelves along the shoreline. Their unique form and activity depend on specific physical conditions during winter months.
Role of Waves and Water Movement
Waves play a crucial role in forming ice volcanoes. As winds push waves toward the shoreline, the water carries energy that breaks through weak spots in the newly formed ice shelf.
This force causes water to spray upward through cracks in the ice, carrying slush and forming hollow cones as it refreezes. Larger, repeated waves lead to more pronounced and taller cones.
Wave motion also helps maintain the volcano's vent. Water and slush flowing up and out of the cone’s opening prevent it from sealing, allowing eruptions to continue as long as the active wave action lasts. When wave activity drops, formation slows or stops.
Impact of Freezing Temperatures
Consistently cold temperatures are essential for ice volcano formation. Air below freezing ensures that each spray of water ejected by waves solidifies quickly, building up the sides of the cone.
Freezing temperatures allow new layers of ice to accumulate with every burst of water, so the structure grows outward and upward. If temperatures rise above freezing, the ice can melt or weaken, possibly leading to collapse.
Extremely cold spells can speed up the process by making sure the ejected water freezes almost instantly. This makes the ice volcano more stable and can result in wider cones with thicker walls.
Development of Ice Shelves
The initial stage of ice volcano formation relies on the development of ice shelves. These shelves form when surface water along the shoreline freezes and extends outward from land.
Ice shelves act as a platform for waves to build cones. They create a barrier that traps wave energy, forcing water up through the ice instead of simply washing over the shore.
The thickness and strength of the ice shelf determine how many ice volcanoes can form and how long they last. Thin or unstable shelves may break, ending the eruption phase, while thick shelves allow larger, more persistent cones to develop.
Physical Characteristics and Structure
Ice volcanoes are unique formations that develop along the shorelines of the Great Lakes during winter. Their structure is shaped by cold temperatures, wave action, and the dynamics of the seasonal ice cover.
Typical Shapes and Sizes
Ice volcanoes form as circular or conical mounds that rise above the surface of the ice shelf. The “crater” at the summit functions as a vent, which may look similar to volcanic features but is formed by wave pressure, not magma.
Typical heights range from just a few feet to over 15 feet tall, depending on wind, waves, and temperature. Width varies from several feet to more than 30 feet at the base. Many ice volcanoes are clustered together, giving the shoreline an uneven, bumpy appearance.
Their symmetry can be irregular, with sloped sides leading to the central opening. Hard-packed snow and lake spray often coat the surfaces, making the mounds appear white or gray. These formations only occur where the ice cover meets open water and waves remain active.
Cracks and Eruptions
Cracks almost always develop in the ice around and within the volcanoes. These cracks weaken the surrounding ice, especially where the ice cover transitions to open water. Thin spots or fissures sometimes circle the base, making these areas unstable and dangerous for walking.
When strong waves strike the ice shelf, water is forced up through the central vent, spraying liquid and slush into the air. This eruption process can repeat many times throughout a winter. Each eruption widens or reshapes the vent, while deposited ice thickens the mound around it.
Key features of eruptions:
Sudden bursts of water and slush
Changes to vent size and shape
Formation of new cracks or fissures
The interplay of cracks, ice cover, and constant eruptions leads to continuous changes in the structure and stability of ice volcanoes over time.
Occurrence on the Great Lakes
Ice volcanoes regularly form along the shorelines of several Great Lakes during winter, shaping distinct landscapes and attracting both scientists and onlookers. These features depend on specific temperature, ice cover, wind, and wave conditions unique to each lake and shoreline.
Where Are Ice Volcanoes Most Common?
Ice volcanoes are most frequently found on the southern and eastern shores of the Great Lakes, where winter wind patterns and open water persist. Strong winds push waves under developing ice sheets, forcing water and slush to erupt through weak spots, creating cone-shaped mounds.
Shorelines that receive direct wind-driven waves from large stretches of open water, known as fetch, are especially prone. Local geography, such as gently sloping beaches or sandbars, further increases the frequency of these winter formations.
The exact locations can shift each year depending on overall ice thickness and the prevalence of open water. Not all beaches will see ice volcanoes in the same winter, and some years see far fewer structures than others.
Lake Michigan and Notable Shores
Lake Michigan is particularly well-known for its impressive ice volcanoes, especially near popular beach areas along its eastern shoreline. Oval Beach in Saugatuck and the Indiana Dunes frequently see these formations due to their exposure to prevailing westerly winds and consistent wave action.
Heavy wave activity combined with partial ice cover drives the repeated ejection of slush and water, forming cone-like mounds that may reach several feet in height. The beaches along the eastern shore are especially suited, as the wind travels unbroken over the water before hitting the beach.
These features are often transient, sometimes lasting just a few days before melting or being flattened by changing winds or temperatures. Beaches near larger cities such as Chicago rarely see significant ice volcano activity due to urban shoreline modifications and reduced natural ice formation.
Ice Volcanoes on Lake Erie
Lake Erie’s shallow depth and relatively short freezing period contribute to the rapid development and destruction of ice volcanoes. The lake’s southwestern shore, especially in Ohio and parts of Pennsylvania, sees regular eruptions when cold snaps arrive but ice cover is incomplete.
Wind direction matters significantly. When winds push across long distances of water, reaching the south shore, built-up waves inject enough energy to burst through forming ice. These eruptions carry lake water and slush far onto the ice surface, creating clusters of crater-like volcanoes.
In some winters, rapid freeze-thaw cycles can cause these formations to be short-lived. On some occasions, Lake Erie’s ice volcanoes form in large groups, spaced along several miles of shoreline, and then collapse or freeze solid within days.
Formation on Lake Ontario
Lake Ontario also experiences ice volcano formation, particularly along its southern and eastern flanks in New York State. The combination of prevailing northwesterly winds and wide expanses of open water during early winter create ideal conditions for eruptions.
Unlike larger lakes, Ontario’s slightly milder winters and smaller fetch result in lower, but often denser, clusters of ice volcanoes. Beaches such as those near Oswego and Sodus Bay offer frequent observations of these mounds, especially during cold spells with active wave movement.
Lake Ontario’s shores can see significant tourism during peak formation periods, though the unpredictable nature of ice thickness makes the area hazardous for walking. The volcanoes here erode quickly, either from warming temperatures or new snowfall burying them in deeper drifts.
Ice Volcanoes on Lake Superior
Lake Superior’s vast shoreline and cold winter climate create ideal conditions for the formation of ice volcanoes. These unique features result from a specific interaction of wind, waves, and a partially frozen lake surface.
Formation Near Shoreline
Ice volcanoes form most often along the shoreline of Lake Superior, where strong winds and waves push water toward the edge of the frozen lake. When this moving water hits the accumulating ice, it forces slushy water upward through cracks or weak spots.
This process creates cone-shaped mounds, which can range from a few feet to over ten feet tall. The continuous waves cause repeated eruptions through these vents, building up the volcano structures further.
Cold air and low winter temperatures help maintain the frozen surface, making these features more stable and visible for days or even weeks. Ice volcanoes are temporary and dissipate as temperatures rise or wave action changes.
Unique Features of Lake Superior Ice Volcanoes
Unlike similar phenomena on smaller lakes, ice volcanoes on Lake Superior are often larger and more dramatic due to the lake’s considerable size and frequently harsh weather. The wide shoreline allows for multiple volcanoes to form in clusters, sometimes appearing as a field of icy cones.
Lake Superior’s powerful and persistent waves can push water great distances under the ice, resulting in stronger eruptions and more pronounced structures. The emerging water can carry pebbles, sand, and debris, sometimes leaving a ring of materials around the base.
Photographers and visitors are often drawn to these features along the Marquette shoreline, where ice volcanoes have been observed and filmed. The combination of large cones and turbulent water creates a striking scene unique to the Great Lakes region.
Environmental and Safety Considerations
Ice volcanoes form in harsh winter conditions and attract curiosity, but they also present environmental hazards and safety risks. The lakefront environment can quickly change, with ice stability varying from day to day.
Dangers and Unstable Surfaces
The ice around volcanoes often appears solid, but it is frequently hollow, thin, and unstable. These formations are built from repeated wave action and freezing temperatures, which means the surfaces may not support a person's weight.
Breaking through can result in falling into frigid water trapped below the ice, leading to hypothermia or drowning. Rescues are difficult due to the unpredictable structure and varying thickness around the mounds.
Safe distances should be maintained from the edge of frozen lakes. Signs and barriers may be present, but ice can be deceptive even a few feet from shore.
Warnings from the National Weather Service
The National Weather Service (NWS) regularly issues public advisories concerning conditions on frozen lakes, especially when ice volcanoes are present. They often emphasize that walking on or near shelf ice is dangerous due to hidden cracks and air pockets.
NWS notices highlight specific risks such as shifting ice sheets and the potential for sudden collapses. These warnings are updated to reflect day-to-day weather and temperature fluctuations, making real-time information critical.
Visitors are urged to check official updates before visiting and to avoid venturing onto shelf ice regardless of how stable it may look. Following these warnings reduces emergency incidents and supports public safety efforts.
Rarity and Climatic Conditions
“Ice volcanoes” are uncommon features that rely on specific natural conditions, especially stable ice cover and consistently freezing temperatures. Their formation and frequency are closely linked to weather variability and local winter climate patterns.
Weather Patterns Favoring Ice Volcanoes
Ice volcanoes develop primarily in locations with fresh water and prolonged cold spells. The Great Lakes region is a prime example, where the combination of sub-freezing temperatures and active wave motion causes water to spray through openings in the ice shelf and freeze into mound-like structures.
For ice volcanoes to form, a sufficiently thick ice shelf must first develop along the shoreline. Wind-driven waves then push water beneath or through this shelf. The water is forced up through cracks, creating conical ice mounds as it rapidly freezes upon exposure to cold air.
Key requirements include:
Sustained below-freezing air temperatures
Strong, persistent wind to generate large waves
Solid ice cover near the coast but with some flexibility for water movement
Salinity also matters—freshwater lakes freeze more readily than oceans, which makes the Great Lakes more favorable for this phenomenon.
Seasonal Occurrence
Ice volcanoes are most likely to form in the coldest months, typically between January and early March. During this period, air temperatures frequently drop well below freezing, allowing shoreline ice to build up to the necessary thickness.
As winters in the Great Lakes region have become milder in recent years, the frequency and persistence of ice volcanoes have decreased. Warm spells can interrupt the freezing process and destabilize the ice shelf, causing any existing cones to break down or fail to form at all.
Their presence is thus both seasonal and erratic, dependent on continuous cold and relatively undisturbed shoreline ice. Some years may see numerous ice volcanoes, while other years might see none if the winter is especially warm or stormy.
Spectacle and Impact on the Landscape
Ice volcanoes are striking seasonal features often forming along the Great Lakes shorelines, capturing the attention of both scientists and casual observers alike. These temporary structures not only add a unique visual element to winter landscapes but also interact with and alter the shape of the shoreline in several ways.
Visual Appeal and Tourism
Ice volcanoes, with their cone-like mounds and occasional eruptions of icy water, draw crowds to sites such as the shores of Lake Michigan and Lake Superior.
Locals and tourists often visit these areas to photograph or observe the natural phenomenon. Social media helps spread images and drone footage, increasing public interest and boosting off-season tourism.
Many visit specifically for the rare sight, contributing to local economies during winter. Recreational activities like guided walks sometimes focus on viewing these features, though authorities often warn of thin ice and other hazards.
The appearance of dozens of icy cones extending into the frozen lake creates a landscape not seen at other times of year. This brief transformation of the shoreline entices visitors who might otherwise avoid the area during cold months.
Erosion and Shoreline Changes
Ice volcanoes play a role in reshaping the shoreline each winter.
As waves build up cones of ice, they act as natural barriers, absorbing wave energy that would otherwise erode the land behind them. This helps to temporarily protect fragile sections of shoreline from direct wave impact and ice scour.
However, ice volcanoes are not permanent. As weather warms and structures collapse, accumulated debris and broken ice can contribute to changes in shoreline sediment distribution.
Repeated cycles of formation and destruction can slightly alter the contour of beaches over time. The seasonal nature of their impact means changes are usually subtle, but over many winters, they can help shape the long-term character of Great Lakes shorelines.
Scientific Research and Monitoring
Researchers actively investigate the formation and behavior of ice volcanoes along the Great Lakes using on-site field studies and advanced monitoring technology. Scientific efforts focus on understanding the conditions that produce these features and documenting their impacts on the lakes’ dynamic shorelines.
Studies Conducted on the Great Lakes
Field studies across Lake Michigan, Lake Erie, and other Great Lakes have identified ice volcanoes as seasonal features linked to cold snaps and fluctuating ice cover. Researchers note that these structures tend to form when wave action forces water up through weak points in a rim of shore ice, resulting in conical mounds of ice and snow.
Specific investigations have mapped the locations, sizes, and lifespans of ice volcanoes. Observations reveal that their distribution often depends on wind patterns, wave energy, and temperature variations. Studies also look at the relationship between ice volcanoes and other coastal features like the “icefoot” and ice ridges, providing a better picture of nearshore ice morphodynamics.
Rain, warmer weather, or shifting ice can quickly erode or collapse these formations. Long-term monitoring helps scientists track seasonal patterns and connect ice volcano activity to broader climate fluctuations across the region.
Use of Remote Sensing and Observation
Modern monitoring increasingly relies on remote sensing tools such as radar and satellite imagery. These technologies allow scientists to observe changes in ice cover and detect ice volcano activity even under challenging weather or remote locations.
Multispectral imagery and high-resolution aerial surveys contribute to detailed mapping of shoreline ice formations. Researchers can compare historical data to current images, identifying trends and anomalies over time.
Remote sensing enables more effective, large-scale observation of the Great Lakes. This helps in forecasting where ice volcanoes might form and in assessing their role in shoreline change, erosion, and ecosystem impacts throughout the winter months.
Related Phenomena
Several natural events share key similarities with ice volcanoes on the Great Lakes, especially in how water and ice interact during winter. Understanding these related phenomena helps clarify the unique processes occurring on frozen lakes and their shorelines.
Connection with Tsunamis and Ice Movements
Wave activity is a major driver behind ice volcano formation on the Great Lakes. Strong winds can generate significant waves beneath the ice shelf, causing water to erupt through surface holes—much like a miniature geyser. This process is not caused by volcanic heat, but by wave force pushing water and slush upward.
In rare cases, waves beneath larger sheets of lake ice can resemble a scaled-down tsunami. Once a wave travels beneath a frozen lake, it may crack or break ice, sometimes surfacing at shorelines with bursts of water or ice chunks. While these are not true tsunamis by geological standards, the energy transfer involved is similar in nature, moving water rapidly beneath ice and causing structural shifts.
Other Ice Formations on Frozen Lakes
Frozen lakes across the Great Lakes region display several unique ice formations besides ice volcanoes. Pancake ice, characterized by round, plate-like pieces, frequently forms near shorelines when thin ice collides and piles up. Another common feature is shove ice, where sheets of ice buckle and stack against each other due to wind or current pressure.
Frazil ice is another interesting formation, seen as tiny, loose ice crystals in supercooled water, which can aggregate and thicken to form slushy mats under the surface. Lists of notable formations include:
Ice ridges: Large, pressure-built mounds along shores
Anchor ice: Ice attached to lake beds or submerged objects
Brash ice: Accumulations of broken ice fragments
Each structure is shaped by specific weather and water conditions, reflecting the dynamic environment of frozen lakes in winter.
