Calving as a source of acute and persistent kinetic energy to enhance submarine melting of tidewater glaciers

Abstract

Calving icebergs at tidewater glaciers release large amounts of potential energy. This energy—in principle—could be a source for submarine melting, which scales with near‐terminus water temperature and velocity. Because near‐terminus currents are challenging to observe or predict, submarine melt remains a key uncertainty in projecting tidewater glacier retreat and sea level rise. Here, we study one submarine calving event at Xeitl Sít’ (LeConte Glacier), Alaska, to explore the effect of calving on ice melt, using a suite of autonomously deployed instruments beneath, around, and downstream of the calving iceberg. Our measurements captured flows exceeding 5 m/s and demonstrate how potential energy converts to kinetic energy (EK). While most energy decays quickly (through turbulence, mixing, and radiated waves), near‐terminus EK remains elevated, nearly doubling predicted melt rates for hours after the event. Calving-induced currents could thus be an important overlooked energy source for submarine melt and glacier retreat.