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Research on Athabasca Glacier in the late 1960s constrained ice column deformation rates using borehole inclinometry techniques (Raymond, 1971). This study sought to conduct a field campaign to estimate modern ice deformation rates using an array of 3-axis tiltmeters deployed in Athabasca Glacier. In July 2022, 12 boreholes were drilled to the bed of Athabasca Glacier and instrument strings of three-axis tiltmeters and pressure transducers were deployed at varying depths. The three-axis accelerometers and magnetometer data from these instruments allow for calculation of sensor azimuth and inclination through September 2023. Basal water pressure from sensors with pressure transducers is also reported for this observational period. 

Abstract The time-evolution of glacier basal motion remains poorly constrained, despite its importance in understanding the response of glaciers to climate warming. Athabasca Glacier provides an ideal site for observing changes in basal motion over long timescales. Studies from the 1960s provide an in situ baseline dataset constraining ice deformation and basal motion. We use two complementary numerical flow models to investigate changes along a well-studied transverse profile and throughout a larger study area. A cross-sectional flow model allows us to calculate transverse englacial velocity fields to simulate modern and historical conditions. We subsequently use a 3-D numerical ice flow model, Icepack, to estimate changes in basal friction by inverting known surface velocities. Our results reproduce observed velocities well using standard values for flow parameters. They show that basal motion declined significantly (30–40%) and this constitutes the majority (50–80%) of the observed decrease in surface velocities. At the same time, basal resistive stress has remained nearly constant and now balances a much larger fraction of the driving stress. The decline in basal motion over multiple decades of climate warming could serve as a stabilizing feedback mechanism, slowing ice transport to lower elevations, and therefore moderating future mass loss rates. 

Globally, glaciers are shrinking in response to climate change, with implications for global sea level rise as well as downstream ecosystems and water resources. Sliding at the ice-bed interface (basal motion) provides a mechanism for glaciers to respond rapidly to climate change. While the short-term dynamics of glacier basal motion (< 10 years) have received substantial attention, little is known about how basal motion and its sensitivity to subglacial hydrology changes over long (> 50 year) timescales – this knowledge is required for accurate prediction of future glacier change. We compare historical data with modern estimates from field-collected and remotely-sensed data at Athabasca Glacier and show that, between 1961 and 2019, the glacier thinned by 51 meter ( - 18 %). However, a concurrent increase in surface slope results in minimal change in the average driving stress (-10 kilopascal, - 7%). These geometric changes coincide with a uniform surface slow down of surface velocity (-15 meter a-1, -45%). Historical observations and simplified ice modeling suggest that declining basal motion accounts for most of this slow down (63 % at a minimum). A decline in basal motion can be explained by increasing basal friction resulting from geometric change in addition to increasing meltwater flux through an efficient subglacial hydrologic system. There is some evidence that changes in basal motion in the overdeepened reach are responsible for slowing basal motion several km up-glacier. These results highlight the need to include time-varying dynamics of basal motion in glacier models and analyses. These findings suggest declining basal motion may reduce the flux of ice to lower elevations, helping to mitigate glacier mass loss in a warming climate. 

Lakes in direct contact with glaciers (ice-marginal lakes) are found across alpine and polar landscapes. Many studies characterize ice-marginal lake behavior over multi-decadal timescales using either episodic ~annual images or multi-year mosaics. However, ice-marginal lakes are dynamic features that experience short-term (i.e., day to year) variations in area and volume superimposed on longer-term trends. Through aliasing, this short-term variability could result in erroneous long-term estimates of lake change. We develop and implement an automated workflow in Google Earth Engine to quantify monthly behavior of ice-marginal lakes between 2013 and 2019 across south-central Alaska using Landsat 8 imagery. We employ a supervised Mahalanobis minimum-distance land cover classifier incorporating three datasets found to maximize classifier performance: shortwave infrared imagery, the normalized difference vegetation index (NDVI), and spatially filtered panchromatic reflectance. We observe physically-meaningful ice-marginal lake area variance on sub-annual timescales, with the median area fluctuation of an ice-marginal lake found to be 10.8% of its average area. The median signal (slow lake growth) to noise (physically-meaningful short-term area variability) ratio is 1.5:1, indicating that short-term variability is responsible for ~33% of observed area change in the median ice-marginal lake. The magnitude of short-term area variability is similar for ice-marginal and nonglacial lakes, suggesting that the cause of observed variations is not of glacial origin. These data provide a new context for interpreting behaviors observed in multi-decadal studies and encourage attention to sub-annual behavior of ice-marginal lakes even in long-term studies. 

Abstract. Lakes in contact with glacier margins can impact glacierevolution as well as the downstream biophysical systems, flood hazard, andwater resources. Recent work suggests positive feedbacks between glacierwastage and ice-marginal lake evolution, although precise physical controlsare not well understood. Here, we quantify ice-marginal lake area change inunderstudied northwestern North America from 1984–2018 and investigateclimatic, topographic, and glaciological influences on lake area change. Wedelineate time series of sampled lake perimeters (n=107 lakes) and findthat regional lake area has increased 58 % in aggregate, with individualproglacial lakes growing by 1.28 km2 (125 %) and ice-dammed lakesshrinking by 0.04 km2 (−15 %) on average. A statisticalinvestigation of climate reanalysis data suggests that changes in summertemperature and winter precipitation exert minimal direct influence on lakearea change. Utilizing existing datasets of observed and modeled glacialcharacteristics, we find that large, wide glaciers with thick lake-adjacentice are associated with the fastest rate of lake area change, particularlywhere they have been undergoing rapid mass loss in recent times. We observe adichotomy in which large, low-elevation coastal proglacial lakes havechanged most in absolute terms, while small, interior lakes at highelevation have changed most in relative terms. Generally, the fastest-changinglakes have not experienced the most dramatic temperature or precipitationchange, nor are they associated with the highest rates of glacier mass loss.Our work suggests that, while climatic and glaciological factors must playsome role in determining lake area change, the influence of a lake'sspecific geometry and topographic setting overrides these external controls. 

Brain machine interfaces (BMI) have traditionally been considered for medical prosthetics. They are now being presented as a means to “merge with the AI”. Entrepreneur Elon Musk has begun trialing his Neuralink technology on pigs, and hopes to incorporate human subjects into his clinical trials of a “breakthrough technology” before year end. Independent of the technology’s success to continue through the medical innovation process via the US Food and Drug Administration, it is time to be pondering the social implications of this novel technology. This paper points to some of the questions philosophers and practitioners alike are asking about the potential for BMI. 

Abstract Globally, glaciers are shrinking in response to climate change, with implications for global sea level rise as well as downstream ecosystems and water resources. Sliding at the ice‐bed interface (basal motion) provides a mechanism for glaciers to respond rapidly to climate change. While the short‐term dynamics of glacier basal motion (<10 years) have received substantial attention, little is known about how basal motion and its sensitivity to subglacial hydrology changes over long (>50 year) timescales—this knowledge is required for accurate prediction of future glacier change. We compare historical data with modern estimates from field and satellite data at Athabasca Glacier and show that the glacier thinned by 60 m (−21%) over 1961–2020. However, a concurrent increase in surface slope results in minimal change in the average driving stress (−6 kPa and −4%). These geometric changes coincide with relatively uniform slowing (−15 m a⁻¹and −45%). Simplified ice modeling suggests that declining basal motion accounts for most of this slow down (91% on average and 46% at minimum). A decline in basal motion can be explained by increasing basal friction resulting from geometric change in addition to increasing meltwater flux through a more efficient subglacial hydrologic system. These results highlight the need to include time‐varying dynamics of basal motion in glacier models and analyses. If these findings are generalizable, they suggest that declining basal motion reduces the flux of ice to lower elevations, helping to mitigate glacier mass loss in a warming climate.