The phrase "ash flow" is not correct in written English.
It seems to be a misspelling or misinterpretation of "cash flow," which is a commonly used financial term.
Example: "The company's cash flow has improved significantly this quarter, allowing for new investments."
Alternatives: "financial flow" or "liquidity flow."
Perhaps the "enormous ash flow" your correspondent alludes to might be reduced by more volunteerism and less participation of political operatives.
Geologists were long puzzled, for example, by the presence of a small amount of banded pumice, or volcanic glass, mixed in the great ash flow.
A number of explanations have been offered for the origin of the ash flow in the valley, none of them conclusive.
The T.V.A. and the state have released only the results of tests on water sampled from the Tennessee River just after the spill at a spot six miles away and upstream of the ash flow, which showed that the water at that spot met drinking standards.
Oligocene ash flow tuffs.
These rocks are underlain locally by Oligocene ash flow tuffs.
Ash flows leave deposits known as tuff, which are made up mainly of ash-sized fragments.
Vast areas of Mexico, New Mexico, and Colorado east of the main volcanic arc were blanketed by volcanic ash flows between 38 and 28 million years ago.
These precursors include lava, pyroclastic (e.g., ash) flows and assemblages, and mudflows containing volcanic debris and volcanic alluvium or loess.
During the past two million years, the area around Yellowstone National Park in the western United States has undergone three major caldera collapses involving pyroclastic eruptions of 280 to 2,500 cubic km (67 to 600 cubic miles) of ash flows and ash falls.
These intensely hot ash flows sterilized 400 square km (154 square miles) of land around the volcano, filling valleys with high-temperature deposits as much as 200 metres (660 feet) thick.
