A quantitative investigation was made on the stratigraphic distribution of particulate matter on 3-inch firn cores obtained from a depth of 21 m at Byrd Station, (80° 00' S, 120° 00' W, elev. 1515 m).
Using the techniques developed in this investigation it was possible to determine quantitatively the stratigraphic distribution of particulate matter in the low micron sizes in melted firn samples at one or several size levels. The spacing of the high and low particle counts provided a means of identifying summer and winter zones and, also as an aid in the determination of the annual accumulation of firn. This helps to provide more accurate mass-balance figures for the ice sheet. Volume and estimation of the weight of airborne particulate matter deposited in the firn is calculated from the size-distribution curves. The presence of extremely high particle counts and the unique size-distribution characteristics of a stratigraphic horizon suggests future usefulness for tracing index horizons over broad areas of Antarctica.
The techniques and equipment, including an electronic particle counter (Coulter counter), are described.
The development of these techniques makes the presence of highly dispersed particulate matter in firn a quantitative stratigraphic parameter which can be used in the laboratory or modified for field use. In the field, it can provide correlation with other snow pit measurements as an aid in interpreting annual accumulation in the various firn environments of polar ice sheets.