Shifting Snow....Thought Someone Was Shooting At Us

the girlfriend and i went on a day hike up Spearfish Canyon in Black Hills of S.D. yesterday, it was a nice warm day (mid 50"s) and the sun was shinning the whole day

when we got to the top of the trail we got on a forest service road that was more out in the open than the rest of the trail, the snow was between 2-3 feet deep, after about 10 steps we heard what we thought was a gunshot pass overhead, the only hunting season going on right now is spring turkey, which would mean shotguns and this sounded like a rifle round, anyways we walked another 30 feet and heard another "shot" needless to say we were both a bit freaked, once you can understand maybe a stray bullet, but twice makes you think someone is taking aim at you, after a few more steps it happened again but this time i saw the small line in the snow right in front of me along with the sound and realize it was the snow shifting, i was amazed how far and loud the shifting was, these thin "shifting lines" were 20-40 yards long and quite loud, this was happening on fairly flat ground, kinda neat after we realized what it was

this continued most of the afternoon and we got used to it, but the first couple time it was very unnerving

just wonder if anyone else has experienced this?

here's a couple photos of the day, none out on the road where this occurred tho
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boot

A taut surface like snow crust or ice can act like a speaker, translating small vibrations into big sounds. (especially in dense cold air) We used to love throwing rocks on frozen lakes and rivers to see what kind of freaky sounds they made. Also, ice grains and sand make interesting sounds as they shift and grid against each other.

I think I have had something similar happen while cross country skiing in the Wasatch range of Utah. But I am slightly confused: you said:"what we thought was a gunshot pass overhead". Did you hear something like a bullet zinging through the air above your head? or did you hear a "boom" or "thump" under your feet?

Anyway, we had driven up to some high elevations but gotten to a rolling bench near the foot of the higher peaks. We are skiing along, I heard a muffled "whump". It reminded me of the sound you get if you are carrying a heavy bag of fertilizer or sand or mulch over your shoulders and you throw it down on the ground. I guessed that it meant the snow was very unstable and if the hills had been steeper where we were, avalanche danger would have great. This theory was somewhat confirmed by the fact that- way in the distance we could hear the canons being fired over at the Alpine/downhill ski resorts as they tryed to preempt avalanche by firing their canons into the snow on the peaks. So I figured that the snow was trying to avalanche under our feet, but really could not do much as we were on gentle hills. It was just a guess, but I heard this sound several times.

Could this have been what you were hearing? :confused:

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Originally Posted by BillyBob58

I think I have had something similar happen while cross country skiing in the Wasatch range of Utah. But I am slightly confused: you said:"what we thought was a gunshot pass overhead". Did you hear something like a bullet zinging through the air above your head? or did you hear a "boom" or "thump" under your feet?

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i don't know what a bullet going over head sounds like but, this was exactly what we thought it was the first two times, it was fairly high pitched sound and with the distance and speed it was traveling through the snow, it made you think it was a bullet, i don't know the physics of it but with the trees reflecting the sound it initially sounded like it was overhead when it really wasn't, definitely not a "boom or thump" sound..........hard to describe it, but it was a "zing" sound, and kinda scary till we figured out exactly what it was

boot

I've never heard a "zing", but I have heard some 'pops'. The sounds I have heard have sounded like .22s at best; not overly loud. I wonder if the difference in noise isn't due to the differing composition of the snow. Ours out here is generally light and airy, but generally laminated by the daytime sunlight (we're close to that big yellow thing in the sky out here) melting the top layer, then refreezing at night?

I heard/saw a glacier calf once. Sounded more like a cannon shot followed by a Browning M2 burst. :scared: