Mass loss from the Greenland ice sheet has increased rapidly in the last two decades and has contributed significantly to observed sea level rise. The most pronounced change is occurring where ice sheets are grounded below sea level, due to enhanced interaction with warming ocean waters. However, our ability to predict future sea level rise is hampered by our limited knowledge of these glacial systems, including the regional water mass distribution and circulation responsible for that enhanced ocean-ice interaction. The Petermann Expedition of August 2015 encompassed a broad range of data collection in an effort to characterize the Petermann Glacier system, a marine-terminating glacier with a floating ice tongue that has undergone dramatic changes in the last decade. During the expedition, sonars were used to map the water column, generating a continuous dataset over 30 days. This mapping revealed extensive acoustic scattering layers, so called because the components of the layer – typically zooplankton – cause the acoustic energy to scatter much as it does when it encounters the seabed. The layer was observed to change depth in a spatially consistent manner and corresponded to our general, but limited understanding of the complex circulation pattern in the study area. Shipboard insolation data and satellite-derived light attenuation data were used to rule out response to light as the primary reason for changes in the scattering layer depth. Comparison to salinity and temperature measurements were used to demonstrate a pattern in the scattering layer depth distribution related to circulation, confirming that the continuous record provided by acoustics can supplement point observations of temperature and salinity to provide a more complete picture of regional oceanography and the glacial system as a whole.