Our group is motivated by the need to understand not just how the Earth’s ice masses change, but why. We focus on processes at interfaces (ice-bed, ice-ocean, and ice-air) in order to capture how Earth’s land masses interact with other components of the Earth’s climate system. We construct long, detailed records of dynamic changes of ice sheets from multi-mission remote sensing campaigns to isolate processes and help separate internal variability from long-term changes. For more detailed insight, we compliment remote sensing observations with targeted ground- and air- campaigns, including three-dimensional, high-precision GPS surveys, radio-echo sounding, electromagnetics, and other geophysics tools.
Below is a non-exhaustive list of some of the projects we are currently working on. Because Greenland and Antarctica both react to and drive the Earth’s climate system, teasing out the exact driver of change requires extensive collaboration. We work with glaciologists, engineers, oceanographers, atmospheric scientists, and geologists from around the world to develop a more holistic picture of ice-sheet change. We are always looking for new, exciting collaborations, so get in touch if you are interested in working together to investigate the Earth’s cryosphere.
Subglacial Antarctic Lakes Scientific Access (SALSA)
We know more about Mars than we know about Antarctica’s subglacial environment, but new information about its nature is changing the way we view the continent. The Subglacial Antarctic Lakes Scientific Access (SALSA) project is uncovering new knowledge about this newly explored biome through an integrative study of physical glaciology, subglacial geobiology, water column and sedimentary organic carbon, and geobiological processes in a West Antarctic subglacial lake.
Mines Glaciology works within the larger SALSA umbrella to understanding the coupled ice-water dynamics that govern dynamic subglacial hydrology in Antarctica. We use long-term continuous GPS stations, airborne radar, and satellite radar and laser altimetry to piece together the history of water flow beneath the Mercer and Whillans ice streams and work with our SALSA colleagues to quantify the impact of this rapidly changing water system on sediment transport and geomicrobiology. Read more about our long-term GPS network here.
In January 2019, the SALSA Project set up a field camp of nearly 50 scientists, drillers, and support staff and drilled 3,500 feet into the ice to sample from Mercer Subglacial Lake. After 10 days of sampling, Mines Glaciology installed a permanent fiber-optic cable in the ice column and subglacial lake for distributed temperature sensing, representing the first of hopefully many long-term subglacial observatories in Antarctica.
SALSA EM: Mapping subglacial groundwater in Antarctica
Standard geophysical surveying techniques used in glaciology to image subglacial water (radio-echo sounding and active-source seismology) are not directly sensitive to water content. Ground-based electromagnetic (EM) methods are sensitive to water content and, although they are well-established for high-precision mapping of hydrology in other geological environments, they have not been applied on ice sheets. SALSA EM adapts both passive- and active-source EM techniques to glaciological questions into order to quantify the three-dimensional structure of subglacial water beneath an ice stream.
During November 2018 to January 2019 we carried out an extensive geophysical survey on the Whillans Ice Stream in West Antarctica. Our survey is the first to use magnetotelluric (MT) imaging to map subglacial groundwater water beneath an ice stream. We collected a total of 44 passive MT stations, as well as several active-source electromagnetic (EM) stations using a large loop transmitter system. With these data, we will study the distribution of groundwater at the base of the ice stream at both the grounding line where the ice stream flows into Ross Ice Shelf and at Whillans Subglacial Lake. Our project is in collaboration with Kerry Key (Lamont Doherty Earth Observatory) Helen Fricker (Scripps Institution of Oceanography, UC San Diego).
Many thanks to Phoenix Geophysics for lending us four MTU-5C ultra-wideband magnetotelluric systems and to Phil Wannamaker for his electric field preamp systems.
Read more about our field experience here.