Avoid this situation by learning to read the terrain, tracking the weather, and knowing the conditions before you ski.
ACCEPT RISK WISELY
If you ski on big mountains long enough, chances are you're going to trigger a slide. This is bad. If you find yourself in the path of a slide, though, you can better your odds of surviving by following these rules: Ski fast on steep faces, watch your back, know the terrain, and have a plan.
SKI FAST—AND STAY IN THE FALL LINE
My general rule in avy terrain is to ski as fast as possible (while staying in control). If you ski slowly, you're going to be crisscrossing the fall line, making you more likely to trigger an avalanche, or for an avalanche to pull your feet out from under you.
WATCH YOUR BACK
As you ski your run, continually look over your shoulder to see what the snow's doing behind you. It's a split-second move—like looking to switch lanes in a car—but it could save your life.
USE THE TERRAIN
Your escape route will depend on where you are when the avalanche starts. If you kick it off from the top, try to sidestep uphill as it sloughs out beneath you. If you're caught in the middle, take a 45-degree angle off the slope and try to pull up into higher terrain. If it kicks off behind you, you have a decision to make: the 45-degree angle or a straightline. My choice is to point it, as long as the runout is clear.
HAVE A PLAN
Before you ski a run, always have a backup plan. Scope the line for islands of safety. Visualize yourself getting caught—and surviving. Use the terrain to keep yourself safe. And if you think it's going to slide, then don't ski it.
Disclaimer: Seth Morrison has skied more avalanche terrain than almost anyone in the world. He is also capable of skiing at extremely high speeds—and keeping it in control. Avy experts do not advise trying to outrun an avalanche. Morrison's tip should only be used as a last resort.