Tall coniferous trees reflected in bright turquoise pond

Geology

Why Is Biei Pond Blue? An Eruption's Legacy

Key takeaways

  • A 1988 eruption blocked rivers with lava, forcing construction of an erosion-control dam that created the pond.
  • Aluminium colloids suspended in the water scatter light, producing the distinctive turquoise hue seen in Shirogane Blue Pond.
  • Dead larch trees stand in the water where the forest was flooded, creating an ethereal landscape of skeletal branches.
  • Seven stops including Patchwork Road, Shirogane Blue Pond, Shikisai No Oka, and Farm Tomita, with lunch included in select packages.
  • Full-day guided tour departing from Sapporo with two starting location options and two drop-off points for flexibility.

The Science Behind the Colour

The brilliant blue of Shirogane Blue Pond in Hokkaido results from a phenomenon called Rayleigh scattering, the same process that makes the sky appear blue. When sunlight enters the water, it encounters suspended aluminium hydroxide colloids, microscopic particles left behind by volcanic minerals. These particles scatter shorter blue wavelengths of light while absorbing longer red wavelengths, creating the pond's distinctive cyan hue. The intensity and exact shade of blue vary with the time of day, season, and weather conditions, making each visit unique and explaining why photographers return repeatedly to capture different moods.

The concentration of these colloids determines how vivid the blue appears. On clear days with bright sunlight, the blue pond Japan displays its most saturated colour. Overcast conditions or low light can mute the brilliance, while mineral-rich water flowing into the pond during spring snowmelt can temporarily intensify the effect. This natural chemistry has made the pond a photographer's paradise and a destination for visitors seeking to witness one of nature's most unusual water features in person during a day trip from Sapporo.

Birth of the Pond: The 1988 Tokachi Eruption

Shirogane Blue Pond owes its existence to the 1988 eruption of Mount Tokachi, a volcano located in central Hokkaido. This eruption released massive quantities of volcanic ash and minerals into the surrounding landscape, fundamentally altering the local geography. When engineers constructed a concrete dam on the Biei River shortly after the eruption to control flooding and generate hydroelectric power, they inadvertently created a basin that would capture the mineral-rich runoff flowing from the volcanic slopes above. The combination of volcanic debris and dam construction proved fortuitous, transforming what might have been an ordinary reservoir into an extraordinary natural wonder.

The timing and location made all the difference. The volcanic eruption deposited fine mineral particles across the region, and as rainwater and snowmelt filtered through these deposits, it dissolved aluminium compounds. This mineral-laden water flowed into the newly created reservoir, establishing the chemical conditions necessary for the blue pond to develop its famous colour. Without the eruption's specific mineral content and the dam's construction, this natural phenomenon would not exist, making the pond a direct product of geological chance and human engineering.

Still turquoise lake with bare trees reflected

Larch trees submerged when the dam was built after volcanic mudflows

The Drowned Larch Trees That Stand in Water

One of the most haunting features of the blue pond are the dead larch trees that protrude from the water's surface. These trees were growing on the site before the dam flooded the area, and rather than decompose quickly in the water, they have been preserved by the cool temperature and mineral-rich environment. The trees create an eerie, otherworldly landscape that photographers find endlessly compelling. Some trees still retain branches, while others have been stripped bare by years of exposure to water and weather, their bleached trunks pointing skyward like skeletal fingers. This haunting scenery has become as iconic as the blue water itself.

The larch trees add a layer of melancholy beauty to the landscape that draws visitors seeking something more than a simple scenic photograph. Many visitors spend considerable time on the tour walking along viewing platforms and observation points, studying how light and shadow interact with both the trees and the intensely coloured water surrounding them. The combination of the brilliant blue pond and these ghostly remnants creates a landscape that feels both natural and surreal, making it a must-see destination during any Hokkaido visit.

Shirogane's Japanese Name and Local Identity

The pond is officially known as Shirogane Blue Pond, with 'Shirogane' referring to the area and natural hot springs in the region. In Japanese, the name carries associations with silver and purity, fitting given the crystalline quality of the water. Local residents and tour operators use this name to distinguish the pond from other scenic water features in Hokkaido, emphasizing its unique character and cultural significance to the region. Understanding the Japanese naming convention helps visitors appreciate how the location is integrated into the local landscape and history rather than simply being a picturesque spot.

The area surrounding Shirogane remains relatively small and rural, preserving the natural setting that makes the pond special. Nearby hot springs have drawn visitors for generations, creating a tradition of nature-based tourism in the region long before the blue pond became internationally famous. This context helps explain why the pond developed into such an important destination for the region's economy and identity.

1972

The dam built in 1972 created the conditions that turned this Hokkaido water brilliant blue.

From Hidden Gem to Apple's Wallpaper Fame

The pond's transformation into a global phenomenon accelerated dramatically when Apple selected a photograph of Shirogane Blue Pond as the default desktop wallpaper for Mac operating systems. This decision exposed the pond to millions of computer users worldwide who had no previous knowledge of Hokkaido or Japanese natural attractions. Suddenly, the obscure reservoir became recognizable to anyone who had ever used an Apple computer, creating an unprecedented surge in international interest. Tour operators and tourism boards in Hokkaido quickly recognized the opportunity and began marketing the blue pond as a must-see destination.

The Mac wallpaper phenomenon demonstrates how digital media can transform a location's global visibility overnight. Before this exposure, the pond attracted primarily domestic Japanese tourists and a small number of adventurous international visitors. After Apple's decision, visitor numbers increased exponentially, with international travel blogs and social media amplifying the image even further. Today, many visitors explicitly mention the wallpaper as their reason for including the blue pond on their itinerary, making it one of the most famous examples of a natural site gaining prominence through technology and design choices.

The Photographer Who Revealed the Pond to the World

Before the blue pond became famous globally, local photographer Katsutoshi Shibuya spent years documenting the site through changing seasons and weather conditions. His work captured the pond's unique qualities and helped establish it as a subject worthy of serious photographic attention. Shibuya's images circulated within Japan first, building domestic recognition before the pond achieved international status. His dedication to understanding the location's aesthetic possibilities and returning repeatedly to photograph it under different conditions set a standard that continues to inspire photographers visiting today.

Shibuya's early photographs proved crucial in demonstrating the pond's photographic potential to tourism boards and media outlets. His work showed that the blue pond was not a one-dimensional subject but a location with infinite visual variations depending on time of day, season, weather, and photographic technique. This recognition helped justify investment in access roads, viewing platforms, and tour infrastructure that made the site more accessible to visitors. Today's photography tours and day-trip itineraries from Sapporo owe much to the foundation Shibuya established through his pioneering work.

When the Blue Disappeared: Colour Variations and Vanishing Acts

Despite its reputation for brilliant blue water, Shirogane Blue Pond has experienced periods when the distinctive colour has faded or disappeared entirely. These events typically occur when heavy rainfall dilutes the mineral concentration, or when specific weather patterns reduce light penetration. During particularly wet seasons, the influx of fresh water can overwhelm the balance of aluminium colloids that create the blue hue, turning the water grey or murky brown. Local observers and regular photographers have documented these colour variations across years, creating a body of knowledge about seasonal patterns and environmental factors affecting the pond's appearance.

Understanding these colour fluctuations helps visitors manage expectations when planning their visit to the blue pond. While the water is typically brilliant blue during clear, dry periods, conditions can change rapidly. Tour operators monitor these variations carefully, sometimes adjusting itineraries or timing to maximize the likelihood of encountering the pond at its most vibrant. The possibility of variable conditions actually adds another dimension to the experience for many visitors, who appreciate witnessing how dramatically a natural phenomenon can shift based on factors entirely beyond human control.

See the Blue Pond in person today

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Before you book

Is the Blue Pond natural or man-made?
The pond formed accidentally after a 1988 volcanic eruption blocked rivers. A dam was built to control flooding, creating the blue water body seen today.
Why is the water such a bright blue colour?
Aluminium colloids suspended in the water scatter light, creating the distinctive blue hue. This optical effect intensifies on clear days and depends on viewing angle.
What are the dead trees in the pond?
Larch trees were submerged when the water level rose after dam construction. They remain standing in the pond as a striking natural feature of the landscape.
Has the blue colour ever disappeared?
Yes. The water's colour can fade or change depending on weather, mineral content, and season. Heavy rain or sediment shifts occasionally alter its appearance.
Which volcanic eruption created this pond?
The 1988 eruption of Mount Tokachi blocked river valleys with debris, leading to water accumulation that eventually became the Blue Pond.
Is the Blue Pond water safe to drink or swim in?
The pond is not designated for swimming or drinking. The high mineral content and aluminium colloids make it unsuitable for these activities.
Who first made the Blue Pond famous?
Early photographers captured its striking colour, and it gained international recognition after becoming a featured macOS wallpaper, boosting visitor numbers significantly.
What is the Japanese name for the Blue Pond?
The pond is called Shirogane Blue Pond, located near the Shirogane area. 'Shirogane' refers to the surrounding region in Hokkaido.
Does the tour visit the Blue Pond?
Yes. The itinerary includes a stop at Shirogane Blue Pond as one of seven locations visited during the full-day tour from Sapporo.
What other attractions are included on this tour?
The tour visits Patchwork Road, Shikisai no Oka flower park, Farm Tomita, and a local restaurant. Multiple starting and drop-off points in Sapporo are available.

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