Proglacial river stage derived from georectified time-lapse camera images, Inglefield Land, Northwest Greenland

• Published in: Frontiers in Earth Science
• Main Authors: Goldstein, Seth N., Ryan, Jonathan C., How, Penelope R., Esenther, Sarah E., Pitcher, Lincoln H., LeWinter, Adam L., Overstreet, Brandon T., Kyzivat, Ethan D., Fayne, Jessica V., Smith, Laurence C.
• Other Authors: Institute at Brown for Environment and Society, Brown University
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Frontiers Media SA 2023
• Subjects: General Earth and Planetary Sciences; Greenland; Inglefield Land; glacier; Ice Sheet; Inglefield land
• Online Access: http://dx.doi.org/10.3389/feart.2023.960363; https://www.frontiersin.org/articles/10.3389/feart.2023.960363/full

The Greenland Ice Sheet is a leading source of global sea level rise, due to surface meltwater runoff and glacier calving. However, given a scarcity of proglacial river gauge measurements, ice sheet runoff remains poorly quantified. This lack of in situ observations is particularly acute in Northwest Greenland, a remote area releasing significant runoff and where traditional river gauging is exceptionally challenging. Here, we demonstrate that georectified time-lapse camera images accurately retrieve stage fluctuations of the proglacial Minturn River, Inglefield Land, over a 3 year study period. Camera images discern the river’s wetted shoreline position, and a terrestrial LiDAR scanner (TLS) scan of riverbank microtopography enables georectification of these positions to vertical estimates of river stage. This non-contact approach captures seasonal, diurnal, and episodic runoff draining a large (∼2,800 km 2 ) lobe of grounded ice at Inglefield Land with good accuracy relative to traditional in situ bubble-gauge measurements ( r 2 = 0.81, Root Mean Square Error (RMSE) ±0.185 m for image collection at 3-h frequency; r 2 = 0.92, RMSE ±0.109 m for resampled average daily frequency). Furthermore, camera images effectively supplement other instrument data gaps during icy and/or low flow conditions, which challenge bubble-gauges and other contact-based instruments. This benefit alone extends the effective seasonal hydrological monitoring period by ∼2–4 weeks each year for the Minturn River. We conclude that low-cost, non-contact time-lapse camera methods offer good promise for monitoring proglacial meltwater runoff from the Greenland Ice Sheet and other harsh polar environments.