it is possible that you triggered it and it is possible it is natural.
if it occured while you were skiing than you did trigger it. Slides have been known to be triggered from like 1/2 mile away...so you could have easily triggered one there. The convex slope, as was said above, probably played a role. The cliff to the skiers right as well.
either way, no matter how you look at it your lucky.
not to be an ass, but just curious.
were you wearing beacons/ carrying shovel/probe and skiing with people who knew how to use them? Did you consider avies at all when you were considering your route down?
it looks from the tracks that no one in your group triggered that slide. or you may have. but you were all pretty brave skiers to not ski away as fast as you can as it came towards the tracks and deposited pretty close to the intersect. rocks and sun crust and unstable conditions wil ldo that to you. and end your trip early.
all bets aside. must of been pretty epic to see. you're lucky thats for sure.
wut happened was i was skiin down and as i skied passed that spot it slid...the people i was with were behind me and they stopped and i just kept goin until it stopped
and i wasnt wearin a beacon and i didnt have any of that stuff...it was just off the chairlift and i dont have much big mountain experience other than some trips out west