High-speed landslides can generate air waves, which are also known as air blasts, due to the rapid movement of the landslide mass. The mechanical mechanism behind the generation of air waves by high-speed landslides is complex and involves several factors.

One of the primary factors is the sudden release of energy that occurs during the landslide. As the landslide mass moves downhill, it displaces a large volume of air in front of it. This displaced air creates a high-pressure zone, which propagates outward from the landslide as a shock wave or air blast.

Another factor that contributes to the generation of air waves by high-speed landslides is the fragmentation of the landslide mass. As the mass moves downslope, it can break apart into smaller pieces due to the forces acting on it. This fragmentation creates additional air pockets that are rapidly compressed and decompressed as the landslide moves, generating additional air waves.

The speed and size of the landslide also play a role in the generation of air waves. Larger and faster-moving landslides can generate more powerful air waves than smaller or slower-moving landslides.

Overall, the mechanical mechanism of air wave generation by high-speed landslides is complex and depends on several factors. However, the primary mechanism involves the rapid displacement of air by the landslide mass, which creates high-pressure zones that propagate outward as shock waves or air blasts.