A5030527883- Cryospheric studies and observations
- Landslides and related hazards
- Winter Sports Injuries and Performance
- Arctic and Antarctic ice dynamics
- Planetary Science and Exploration
- Climate change and permafrost
- Astro and Planetary Science
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Spacecraft and Cryogenic Technologies
- Polar Research and Ecology
- Soil Moisture and Remote Sensing
- Geophysical Methods and Applications
- Ionosphere and magnetosphere dynamics
- Underwater Acoustics Research
- Synthetic Aperture Radar (SAR) Applications and Techniques
- Space Exploration and Technology
- Seismic Waves and Analysis
- Icing and De-icing Technologies
- Advanced SAR Imaging Techniques
- Radio Astronomy Observations and Technology
- GNSS positioning and interference
- Geological Studies and Exploration
- Geophysics and Gravity Measurements
- Gamma-ray bursts and supernovae
Stanford University
2016-2025
Palo Alto University
2019-2024
Swansea University
2023
University of Tasmania
2023
ArcelorMittal (Germany)
2023
Pennsylvania State University
2023
The University of Texas at Austin
2011-2022
Jet Propulsion Laboratory
2014-2022
Stanford Medicine
2020
California Institute of Technology
2015
Thwaites Glacier is one of the largest, most rapidly changing glaciers on Earth, and its landward-sloping bed reaches interior marine West Antarctic Ice Sheet, which impounds enough ice to yield meters sea-level rise. Marine sheets with beds have a potentially unstable configuration in acceleration can initiate or modulate grounding-line retreat loss. Subglacial water has been observed theorized accelerate flow overlying dependent whether it hydrologically distributed concentrated. However,...
Abstract The goal of NASA’s Europa Clipper mission is to assess the habitability Jupiter’s moon Europa. After entering Jupiter orbit in 2030, flight system will collect science data while flying past 49 times at typical closest approach distances 25–100 km. mission’s objectives are investigate Europa’s interior (ice shell and ocean), composition, geology; also search for characterize any current activity including possible plumes. be accomplished with a payload consisting remote sensing...
Abstract Geological investigations planned for the Europa Clipper mission will examine formation, evolution, and expression of geomorphic structures found on surface. Understanding geologic features, their any recent activity are key inputs in constraining Europa’s potential habitability. In addition to providing information about moon’s habitability, study is compelling itself. Here we provide a high-level, cross-instrument, cross-discipline overview within mission. fascinating collection...
Abstract We present Bedmap3, the latest suite of gridded products describing surface elevation, ice-thickness and seafloor subglacial bed elevation Antarctic south 60 °S. Bedmap3 incorporates adds to all post-1950s datasets previously used for Bedmap2, including 84 new aero-geophysical surveys by 15 data providers, an additional 52 million points 1.9 line-kilometres measurement. These efforts have filled notable gaps in major mountain ranges deep interior East Antarctica, along West...
Subglacial hydrology in East Antarctica is poorly understood, yet may be critical to the manner which ice flows. Data from a new regional airborne geophysical survey (ICECAP) have transformed our understanding of topography and glaciology associated with 287,000 km 2 Aurora Basin Antarctica. Using these data, conjunction numerical sheet modeling, we present suite analyses that demonstrate potential 1000 km‐long basin as route for subglacial water drainage interior margin. We results analysis...
Significance Thwaites Glacier is one of the West Antarctica's most prominent, rapidly evolving, and potentially unstable contributors to global sea level rise. Uncertainty in amount spatial pattern geothermal flux melting beneath this glacier a major limitation predicting its future behavior contribution. In paper, combination radar sounding subglacial water routing used show that large areas at base are actively response consistent with rift-associated magma migration volcanism. This...
Antarctica's subglacial lakes have two end member geophysical expressions: as hydraulically flat, radar reflective regions highlighted in ice surface topography and sounding profiles (‘definite lakes’), localized sites of elevation change identified from repeat observations (‘active lakes’) that are often found fast flowing streams or enhanced flow tributaries. While ‘definite lakes’ can be readily by high bed reflectivity sounding, the identification characterization less distinct water...
Abstract Radar sounding is a powerful geophysical approach for characterizing the subsurface conditions of terrestrial and planetary ice masses at local to global scales. As result, wide array orbital, airborne, ground-based, in situ instruments, platforms data analysis approaches radioglaciology have been developed, applied or proposed. Terrestrially, airborne radar has used glaciology observe thickness, basal topography englacial layers five decades. More recently, also exploited estimate...
ABSTRACT Several airborne radar-sounding surveys are used to trace internal reflections around the European Project for Ice Coring in Antarctica Dome C and Vostok ice core sites. Thirteen reflections, spanning last two glacial cycles, traced within 200 km of C, a promising region million-year-old ice, using University Texas Institute Geophysics High-Capacity Radar Sounder. This provides dated stratigraphy 2318 m depth at C. Reflection age uncertainties calculated from radar range precision...
The view from the south is, more than ever, dominated by ominous signs of change. Antarctica and Southern Ocean are intrinsic to Earth system, their evolution is intertwined with influences course Anthropocene. In turn, changes in Antarctic affect presage humanity's future. Growing understanding countering popular beliefs that pristine, stable, isolated, reliably frozen. An aspirational roadmap for science has facilitated research since 2014. A renewed commitment gathering further knowledge...
Abstract Surface meltwater that reaches the base of Greenland Ice Sheet exerts a fundamental impact on ice flow, but observations catchment‐wide movement and distribution subglacial water remain limited. Using radar‐sounding data from two seasons, we identify seasonal in western Greenland. Our analysis provides evidence widespread storage beneath wintertime. The winter is located primarily bedrock ridges with higher bed elevations excess 200 m. During melt season moves to troughs. This...
Abstract Surface meltwater runoff dominates present-day mass loss from the Greenland Ice Sheet. In Greenland’s interior, porous firn can limit by retaining unless perched low-permeability horizons, such as ice slabs, develop and restrict percolation. Recent observations suggest that horizons might rapidly during extreme melt seasons. Here we present radar sounding evidence an extensive near surface layer formed following season in 2012. This was still 2017 regions up to 700 m higher...
Abstract. One of the key components this research has been mapping Antarctic bed topography and ice thickness parameters that are crucial for modelling flow hence predicting future loss ensuing sea level rise. Supported by Scientific Committee on Research (SCAR), Bedmap3 Action Group aims not only to produce new gridded maps international scientific community, but also standardize make available all geophysical survey data points used in producing Bedmap products. Here, we document latest...
Airborne radar sounding is an established tool for observing the bed conditions and subglacial hydrology of ice sheets glaciers. The specularity content echoes has also been used to detect hydrologic transition a water system from network distributed canals concentrated channels beneath Thwaites Glacier. However, physical dimensions bodies in these networks have not constrained by observations. In this letter, we use variety simple scattering, attenuation, cross-sectional models provide...
Enhanced submarine ice-shelf melting strongly controls ice loss in the Amundsen Sea embayment (ASE) of West Antarctica, but its magnitude is not well known critical grounding zones ASE's major glaciers. Here we directly quantify bottom losses along tens kilometres with airborne radar sounding Dotson and Crosson shelves, which buttress rapidly changing Smith, Pope Kohler Melting found to be much higher than steady-state levels, removing 300–490 m solid between 2002 2009 beneath retreating...
Abstract. Subglacial roughness can be determined at a variety of length scales from radio-echo sounding (RES) data either via statistical analysis topography or inferred basal radar scattering. Past studies have demonstrated that subglacial terrain exhibits self-affine (power law) scaling behaviour, but existing scattering models do not take this into account. Here, using RES northern Greenland, we introduce framework enables consistent integration topographic-scale with the electromagnetic...
Definitive interpretation of ice-sheet basal conditions from radar-sounding data beneath outlet-glacier grounding zones and shear margins can be problematic due to poorly constrained spatially variable englacial attenuation rates losses propagation through a rough ice surface. To correct for rates, we developed novel radar analysis approach that provided improved empirical correction by fitting linearly along profiles the interior zone. We also corrected ice-surface using surface echo...
Abstract Subglacial topography is an important feature in numerous ice-sheet analyses and can drive the routing of water at bed. Bed primarily measured with ice-penetrating radar. Significant gaps, however, remain data coverage that require interpolation. Topographic interpolations are typically made kriging, as well mass conservation, where ice flow dynamics used to constrain bed geometry. However, these techniques generate unrealistically smooth small scales, which biases subglacial...
A possible analog for saline lakes on planetary ice bodies lurks beneath a Canadian Arctic cap.
Antarctic subglacial lakes can play an important role in ice sheet dynamics, biology, geology, and oceanography, but it is difficult to definitively constrain their character locations. Subglacial lake locations are related factors including heat flux, surface slope, thickness, bed topography, though these relationships not fully quantified. Bed topography particularly for determining where water flows accumulates, digital elevation models of the rely on interpolation unrealistically smooth,...
ABSTRACT Englacial temperature is a major control on ice rheology and flow. However, it difficult to measure at the glacier ice-sheet scale. As result, models must make assumptions about englacial rheology, which affect sea level projections. This problematic if fundamental processes are not captured by due lack of observationally constrained values. Although radar sounding data have been exploited constrain structure Greenland sheet using layers, this approach limited areas depths where...