Depths Observations were taken by several groups of people along elevation transects within the catchment. Five snow depths observations were made within a 1 m radius every 10 m along the transects. Depths were determined using an avalanche probe and were recorded in mm. It was not uncommon for the snow depth to be greater than the probe in which case the depth was recorded as being greater than the probe length. The five measured depths and average are provided for each location. Density Density measurements were made approximately once per transect. Density observations were made either by sampling a known volume of snow at measured intervals down the wall of a snow pit and weighing them (using either a mass balance, or a calibrated snow density scale e.g. as manufactured by Winter Engineering), or by using a Mt Rose snow sampler. The depth of the snow often prevented the density observations from being taken all the way to ground. Density observations are provided for every snow sample, giving top and bottom depths of the sample. For a Mt Rose Sampler, this is a single density for up to a 4 m depth. For pit observations this a density for each 0.1 m depth. Locations Locations were recorded using a hand held GPS (+/- 10 m horizontal). New Zealand Map Grid was used. Position coordinates have been checked by plotting the points and subjectively asessing whether the positions are sensible. Points that are unreconcilable are noted as -9999 Note that NZMG coordinates use the NZGD1949 datum. Where provided, elevations were estimated based on barometer, GPS or map readings, and were recorded in metres. Raw data The data provided here has been transcribed from field notebooks. Errors may exist as a result of the original note taking and/or from the transcription. If an error is suspected, please contact Tim Kerr ([email protected]) so that the error can be checked against the original field books. These data were collected with the generous assistance of many volunteers from New Zealand's snow and ice research community. Funding for the observations was provided by the NIWA capability fund. Acknowledgement of NIWA when using these data is appreciated and assists with promoting future snow and ice research programmes. Any communication regarding this data is welcomed and should be directed to [email protected]