2018-2019 Antarctic

This project will sample firn air and shallow ice to a depth of about 233 meters at the Law Dome high-accumulation coastal site in East Antarctica. The goal of the project is to obtain measurements of paleo-atmospheric carbon-14 of carbon monoxide back to the 1800s when reactive trace gas emissions from human activity were minimal. These measurements will help to constrain changes in the oxidizing capacity of the atmosphere during the industrial period. The Badger-Eclipse Drill will be used to create the borehole for the firn air sampling. The 4-Inch Drill and Blue Ice Drill will be used to collect the ice core samples.

This project will utilize the Intermediate Depth Logging Winch to lower a series of optical+UV and radio sensor packages into the South Pole Ice Core (SPICEcore) borehole to the full depth of the hole (1751 m). The science goals include measurements of the radio absorption length of the ice from 100-1000MHz, radio birefringence in the ice, and ice index of refraction, all measured as a function of depth and ice temperature. The science team is interested in the optical scattering, absorption lengths, and luminescence as a function of depth and optical wavelength from the visible into the ultraviolet.

The McMurdo Dry Valleys Long-Term Ecological Research (MCM-LTER) Program is an interdisciplinary and multidisciplinary study of the aquatic and terrestrial ecosystems in an ice-free region of Antarctica. The MCM-LTER has studied Dry Valleys ecosystems since 1993 and observed their responses to climate variations over time. Landscape connectivity, such as streams connecting glaciers to lakes, and lake level rise connecting upland soils, is recognized to be influenced by climate and geological drivers. This physical connectivity facilitates biotic linkages and enables gene flow among the endemic microbial communities. Researchers hypothesize that increased ecological connectivity within the Dry Valleys will amplify exchange of biota, energy, and matter, homogenizing ecosystem structure and functioning. During the MCM-LTER program, researchers will examine (a) how climate variation alters connectivity among landscape units, and (b) how biota (species, populations, and communities) are connected across this heterogeneous landscape, using state-of-the-art science tools and methods, including ongoing and expanded automated sensor networks, analysis of seasonal satellite imagery, biogeochemical analyses, and next-generation sequencing. Researchers will use the Sediment Laden Lake Ice Drill to make holes in the permanent lake ice of the McMurdo Dry Valleys for access to deployed equipment and melting out cables in the ice.

This project will investigate areas in the Antarctic Peninsula where water from summer melting of snow drains down into the deeper snow (firn) and remains as a water-flooded snow layer throughout the Antarctic winter. These zones are called firn aquifers. The project aims to confirm indications from satellite data that these areas exist on the Wilkins Ice Shelf and the George VI Ice Shelf coast. Persistent water in the upper layers of an ice shelf can destabilize the ice shelf and cause it to fracture and disintegrate or, on a non-floating ice sheet, can cause it to flow faster by draining to the bottom of the ice and reducing the friction between bedrock and glacier.

This year's fieldwork is centered on shallow ice-core drilling (using the IDDO Hand Auger) to about 60 meters depth at the southern Wilkins Ice Shelf and the southern George VI Ice Shelf. In addition to drilling one or two cores at each of the sites, researchers will conduct ground-penetrating-radar surveys of the area around the cores (about 60 line-km at each site) to determine the varying depth and extent of the aquifers. They will also install weather stations at each site (automated meteorology–ice–geophysics observing stations, AMIGOS) with a sensor array that will measure weather, snow temperature and accumulation, and melt-season duration and intensity. As part of the ice coring, the researchers will also measure snow density and temperature in recovered ice.

The 2018-2019 field season for the Rapid Access Ice Drill (RAID) project will consist of maintenance and upgrades only, with no testing of ice drilling. Upon request by the PIs, IDP is deploying one engineer to serve as the team leader for the maintenance season.