The phrase "ash cover" is correct and usable in written English.
It can be used to describe a layer or coating of ash, often in contexts related to volcanic activity or the aftermath of a fire.
Example: "After the eruption, the landscape was blanketed in a thick ash cover, making it unrecognizable."
Alternatives: "ash layer" or "ash blanket".
While metres of ash cover the ground, obscuring glaciers and other features, streams of lava can be seen flowing just below the surface.
While much has subsequently been eroded from unstable and/or steep slopes, an ash cover remains intact on more gentle stable slopes and caps alluvial terraces.
These surface effects, especially soil and ash cover and the lack of any remaining vegetative cover, directly relate to potential postfire watershed response processes.
The leachate quality from the ash cover is expected to have a minor influence on overall landfill leachate quality because the amounts generated from the ash covers were low, <3 30 l (m2 yr)−1.
During one year, we monitored the vegetation, litter, soil properties, and ash cover of five ditches that were being unmanaged, dredged, mowed, burned, and chemically weeded, respectively, with timing and frequency as generally operated by farmers in the study area.
Also, the edge of the ash-affected area displays high values of the indices (mostly with LG and ARI): this suggests that vegetation which recovers after being affected by a thin ash cover is in a better state than before the eruption.
Four to six feet of ash covered 250 to 400 acres in the area.
A choking haze of smoke and ash covered the mountain, creating dusk at noon.
A carpet of dust, pencil shavings and cigarette ash covered the worn linoleum floor.
A sky so totally black and ash covered that you'd think there's a volcano blowing up.
Heavy white ash covered the runways at the airport in nearby Yogyakarta, forcing it to close Friday, The Associated Press reported.
