NSFPLR-NERC: Thwaites-Amundsen Regional Survey and Network (TARSAN)

Lead Research Organisation: University of East Anglia
Department Name: Environmental Sciences

Abstract

Thwaites and neighboring glaciers in the Amundsen Sea Embayment (ASE) are rapidly losing mass in response to recent climate warming and related changes in ocean circulation. Ice-sheet models suggest that the mass loss from the ASE will further accelerate in the near future, initiating an eventual collapse of the West Antarctic Ice Sheet (WAIS), raising the global sea level by up to 2.5 meters in as short as 500 years. Such model predictions, however, are still lacking spatially and temporally detailed understanding of the dominant processes at and near grounding zones and the atmospheric and oceanic drivers of these processes. The proposed project aims to constrain these dominant processes affecting the Thwaites and the Dotson Ice Shelves, as well as the grounded ice mass buttressed by these ice shelves. Specific objectives are: 1) to install atmosphere-ice-ocean multi-sensor remote autonomous stations (AMIGOS) on the ice shelves for two years to provide sub-daily continuous observations of concurrent oceanic, glaciologic, and atmospheric conditions; 2) measure ocean properties on the continental shelf adjacent to the ice-shelf fronts (using seal tagging, glider-based and ship-based surveys and existing moored and CTD-cast data) and into the sub-ice-shelf cavities (using Autonomous Underwater Vehicles AUVs) to detail ocean transports and heat fluxes affecting the ice-shelf base; and 3) constrain the current ice-shelf and sub-ice-shelf cavity geometry, ice flow, and firn properties for the two ice-shelf sites (using radar, active-source seismic and gravimetric methods) to better understand the impact of ocean and atmosphere on the ice-sheet change.

Planned Impact

Public Engagement and Educational Outreach: Science writer Doug Fox (inc. National Geographic, Discover, and Scientific American) will be embedded with the field team and write a series of articles highlighting the science and the societal impacts of this work. Fox's focused, in-depth coverage of the research will be coupled with a social media campaign: "Live from the Ice". This social media campaign will include a weblog and Twitter feed that tells stories and announces intriguing observations in real time based on the measurements from the Iridium-uplinked AMIGOS-III data and tagged seals. The general model will follow the highly successful NSIDC Arctic Sea Ice News and Analysis website and the NASA Curiosity "Martian Diaries" , and @MarsCuriosity Twitter feed. The website will be hosted by NSIDC and include discussion of background concepts relating ice-shelf, ocean, and atmospheric processes. Monthly entries will include blogs, video blogs, or short educational videos, depending on the content and message, geared toward middle-school level science students and the science-interested public. The blog, Twitter feed, and other social media would be told from the perspective of sensor system at the edge of the ice, a tag on a seal, or the Autosub. The topics would range from the 'personal' - such as describing a storm or a cold weather event in the context of the Antarctic climate - to the expansive, such as discussing the Antarctic ice-sheet, climate change, and ocean conditions and events. One targeted audience for the blog is middle and high school students. Members of the public will be able to "adopt" a seal, and see the location of their seal on the website in real time, with the warmest and coldest water they encountered and the depth they dived to, superimposed on a sea ice image each day. We will publicize the social media feeds through the US National Science Teachers Association and UK Teacher-Scientist Network, and provide an alternative email listserv for teachers to follow all "Live from the Ice" stories. We will engage with the public early on in the project so that they can follow the project from start to finish. For selected stories, we will provide an annotated spreadsheet file with data, calculations, and plots for teachers to integrate into their teaching activities. AMIGOS-III and seal-tagging data including movement patterns of the seals will also be presented as interactive displays for schools and public science meetings incorporating live data feeds.The collaborative team members regularly participate in K-12 outreach efforts through local school presentations and field workshops, and would continue to conduct these during the proposed work.
 
Description We have measured for the first time the water masses flowing under the Thwaites ice shelf.
We showed the changes in ocean circulation caused by the retreat of the Pine Island Glacier.
We measured the winter time meltwater using sensors on seals' heads, for the first time.
Exploitation Route Ocean modellers might evaluate their models against these results.
Sectors Environment

 
Title Gravity-derived bathymetry for the Thwaites, Crosson and Dotson ice shelves (2009-2019) 
Description This dataset is an estimate of sub ice shelf bathymetry beneath the Thwaites, Crosson and Dotson ice shelves. The output bathymetry is derived from a new compilation of gravity data collected up to the end of the 2018/19 field season. The input gravity dataset includes airborne data from Operation Ice Bridge (OIB) and the NERC/NSF International Thwaites Glacier Collaboration (ITGC), and marine gravity from the R/V Nathaniel B. Palmer cruise NBP19-02. The recovered bathymetry was constrained by swath bathymetry and onshore airborne radio-echo depth sounding data in the surrounding area. Ice shelves mask the critical link between the ocean and cryosphere systems, and hence accurate sub ice shelf bathymetry is critical for generating reliable models of future ice sheet change. Included in the data release is the input free air gravity data, constraining bathymetry/sub-ice topography, and output gravity derived bathymetry. This work was funded by the British Antarctic Survey core program (Geology and Geophysics team), in support of the joint Natural Environment Research Council (NERC)/ National Science Foundation (NSF) International Thwaites Glacier Collaboration (ITGC). Additional specific support came from NERC Grants: NE/S006664/1 and NE/S006419/1, and NSF Grants: NSF1842064, NSFPLR-NERC-1738942, NSFPLR-NERC-1738992 and NSFPLR-NERC-1739003. 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
URL https://data.bas.ac.uk/full-record.php?id=GB/NERC/BAS/PDC/01332
 
Description ITGC launch press 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Media (as a channel to the public)
Results and Impact Press releases for the beginning of the ITGC. Many interviews with radio, TV (BBC News), print media and online media.
Year(s) Of Engagement Activity 2018