A Mogul Field is Born
A few days ago, as I was riding the Empire Express chairlift, I overheard a couple’s conversation about how moguls were created. I listened to the answer the husband gave, smiled and remained silent. I felt compelled to do some research, even though I’ve been around moguls all of my life, and knew that these snow formations are created in very strange ways. As you may know, some moguls are natural, and others are created artificially for the purpose of freestyle competition. So, I zeroed-in on the natural ones. We’ll discover the “man-made moguls” in a subsequent blog…
The creation of natural moguls begins through the repeated passage of skiers following the same “line” through the snow. When the snow is fresh, or soft enough, snow gets pushed to the side of the turn, away from the skis. This creates a curvy snow mound on the periphery of the turn that grows with each skier’s turn. This snow build-up is caused by the skis cutting a rounded trough into the snow that also gets deeper as skiers follow the path.
At the same time, snow is also moved from top to bottom, as the ski slows down, it brings snow from the top of the mogul to that of the mogul below. The formation of mogul is thus a three-dimensional process that is also a continuing story about accumulation and erosion of snow. There’s a point where the mounds of snow created on either side of the tracks turns into a large, rounded bump and the trough becomes a wide, rounded groove.
As the snow builds up higher, more people ski around the higher snow and thus push more snow against the growing mound. There is also a point when snow piles exceed a certain critical size and skiers choose to bypassing them. By doing so, they contribute to accentuate the peaks and valleys that have now given birth to moguls. What used to be a rounded top, is now taking a teardrop shape.
As the process continues, the choices of available path become fewer and fewer, skiers will tend to follow the “paths” already delineated between the bumps. One could say that the appearance of a regular pattern of bumps is a very good example of self-organization. So you have it: repeated skiing following the same path create moguls. When the slope is wide enough to accommodate a number of parallel paths, a complete, beautiful mogul field soon takes form, like the one we typically see on Empire Bowl.
This basic theory is unfortunately too simple. There are variables that cause vast variations in the appearance of moguls. That’s right, the first bump is never created in an orderly manner. Skis go a certain way and not necessarily in the direction desired by the skier. Likewise, bumps pattern, shape and size will vary with each individual’s height, weight, speed, as well as technical ability.
Then, there’s ski length, snow quality (whether it’s hard or soft) and slope grade that also plays a role. Now you can appreciate, how uncertain and even quite chaotic this formative process can be.
Mogul fields often create angst for beginner and intermediate skiers. The mere sight of them usually conjures complexity, uncertainty, confusion and almost every time, fear. This doesn’t need to be. In observing a mogul field, it’s easy to see that all moguls have relatively flat tops. Just like a giant staircase, this series of flat tops can be used to “walk-down” the hill with skis on. As an added advantage, each mogul top gathers soft clumps of snow which slows a skier down and lets the skis pivot easily into the next turn.
To conquer the moguls with the least amount of speed, you’ll want to consistently turn on the crest of the moguls and stay out of the troughs. This makes negotiating a bumpy hill child’s play, making for a safe and fun experience. Of course, if you can’t muster the courage to attempt this on your own, the next best way to successfully address any “mogul phobia” is to ask a ski instructor to familiarize yourself with the strange, yet quite natural elements, one mogul at the time. You’ll soon discover that the battalions of moguls that used to scare you will not just become your friends, but will develop into an endless source of fun!
Deer Valley has some of the best mogul fields I’ve seen. It’s almost magic how they develope in such a short period of time.
I am so fascinated by how moguls form. Thank you for the inspiration. I can’t wait to overcome my “mogul phobia.”