A landslide (산사태, sansatae) shares an earthquake's basic warning — something foundational giving way — but adds a slower, more visible buildup, since a mountainside sliding away is generally seen coming for at least a moment before it fully happens, unlike the instant shock of an earthquake.
The dream is traditionally read as instability in an area of life you'd assumed was completely solid — often something built up over a long time, mirroring how a mountain or hillside represents years of accumulated stability suddenly failing all at once. Career, long-standing relationships, and financial plans are the areas interpreters most often connect this dream to.
Being caught or buried in the landslide is read as feeling trapped by circumstances that collapsed faster than you could respond — a more serious version of the warning than simply witnessing one from a distance. Escaping in time, especially by noticing the warning signs before the slide fully happens, is read as successfully navigating a crisis specifically because you paid attention early.
Watching a landslide happen to someone else's property or a distant hillside, without personal danger, is read more mildly — awareness of instability nearby, in someone else's circumstances or in a situation you're only indirectly connected to, rather than a direct warning about your own life.