The region, they added, may be the planet's "most geologically active zone."

Moreover, the dam is situated in a seismically active zone.

The reserve pool is not directly connected to the active zone.

This is the most active biologic zone of the world, the vital key to the entire ecological cycle.

Thus, there is the puzzling question of how long any interior active zone has to live.

The smoke drove me back even before I penetrated the edge of the active zone.

We must travel laterally and down to take us out of the active zone.

The gondola was almost into the biologically active zone near the surface.

Virginia is not usually considered to be an active seismic zone.

The quake was located in an active zone of stress and deformation.