Meltwater delivery from the tidewater glacier Kronebreen to Kongsfjorden, Svalbard; insights from in-situ and remote-sensing analyses of sediment plumes

• Main Author: Eleanor F. Darlington
• Format: Thesis
• Language: unknown
• Published: 2015
• Subjects: Earth Sciences not elsewhere classified; Kongsfjorden; Meltwater; Tidewater glacier; Arctic fjord; Buoyant plume; MODIS; Arctic; Kronebreen; Svalbard; glacier; Kongsfjord*; Tidewater
• Online Access: https://figshare.com/articles/thesis/Meltwater_delivery_from_the_tidewater_glacier_Kronebreen_to_Kongsfjorden_Svalbard_insights_from_in-situ_and_remote-sensing_analyses_of_sediment_plumes/9487262

Tidewater glaciers form a significant drainage catchment of glacierised areas, directly transporting meltwater from the terrestrial to the marine environment. Surface melt of glaciers in the Arctic is increasing in response to warmer atmospheric temperatures, whilst tidewater glaciers are also exposed to warmer ocean temperatures, stimulating submarine melt. Increased freshwater discharge not only freshens fjord waters, but also plays a key role in glacimarine sedimentary processes, transporting sediment to glacial fjords. Despite this, the temporal evolution of meltwater production, storage and release from tidewater glacier systems at seasonal and interannual time scales is poorly understood. This leaves large uncertainties in the predictions for future sea level rise, ocean circulation and the impacts on the marine ecosystem. This study focuses on Kronebreen, a tidewater glacier which flows into the head of Kongsfjorden, north west Svalbard. Surface melt produces freshwater runoff, which is discharged from the grounding line as a buoyant, sediment laden plume, which spreads laterally across the surface water. This supraglacial melt is the dominant freshwater source, contributing an order of magnitude more freshwater to Kongsfjorden, than direct submarine melting of the ice face. Calibration of MODIS band 1 satellite imagery with in situ measurements of Total Suspended Solids and spectral reflectance, provides a method to quantify meltwater and sediment discharge. Plume extent has been determined for each cloud free day, from June to September, 2002 - 2013. Analysis of plume extent with atmospheric temperature and modeled surface runoff, gives a source to sea insight to meltwater production, storage and discharge. The extent of the plume changes in response to meltwater; larger plumes form when discharge increases. These results reveal that meltwater discharge into Kongsfjorden lags atmospheric temperature, the primary driver of meltwater production, by over a week during June and July. This is reduced to only ...