Ice Limit Research Articles

Simulation of a former ice field with Parallel Ice Sheet Model – Snežnik study case

Abstract. In this paper, we present a reconstruction of climate conditions during the Last Glacial Maximum on a karst plateau Snežnik, which lies in Dinaric Mountains (southern Slovenia) and bears evidence of glaciation. The reconstruction merges geomorphological ice limits, classified as either clear or unclear, and a computer modelling approach based on the Parallel Ice Sheet Model (PISM). Based on extensive numerical experiments where we studied the agreements between simulated and geomorphological ice extent, we propose using a combination of a high-resolution precipitation model that accounts for orographic precipitation combined with a simple elevation-based temperature model. The geomorphological ice extent can be simulated with climate to be around 6 °C colder than the modern day and with a lower-than-modern-day amount of precipitation, which matches other state-of-the art climate reconstructions for the era. The results indicate that an orographic precipitation model is essential for the accurate simulation of the study area, with moist southern winds from the nearby Adriatic Sea having a predominant effect on the precipitation patterns. Finally, this study shows that transforming climate conditions towards wetter and warmer or drier and colder does not significantly change the conditions for glacier formation.

Historical occurrence of Antarctic icebergs within mercantile shipping routes and the exceptional events of the 1890s

Abstract A major consideration for maritime activity in the Southern Hemisphere is the northern limit of icebergs, or the Southern Ocean Limit Of Known Ice (SOLOKI). This analysis of historical reports of icebergs during Southern Hemisphere voyages from 1687 to 1933 provides a basis for examination of their geographical and chronological occurrence during ~250 years. The analyses use tabulated data from 742 voyages and other reports from many sources, some including first-person descriptions. While these data are dependent on icebergs being reported by mariners, as well as the variable frequency of voyages, they demonstrate distinct periods of exceptional frequency of icebergs occurring in certain localities, particularly the far South Atlantic. Based upon historical records the evidence suggests unprecedented numbers of icebergs were present in southern shipping channels in the 1890s. When these historical observations are combined with modern iceberg drift trajectories, their possible origin can be elucidated. Owing to the numbers of icebergs seen and their geographical spread, our results suggest that this was possibly the largest near-synchronous calvings in the last 300 years, and the northernmost extent of the SOLOKI.

Estimating summer sea ice extent in the Weddell Sea during the early 19th century

Abstract. Over the past 3 decades, discordant trends in sea ice extent have been observed between the Arctic and Antarctic regions. Arctic sea ice extent has been characterised by a rapid decline, whereas Antarctic sea ice extent, while highly variable interannually, has tended to increase. Climate models have so far failed to capture these trends. Coupled with the limited pre-1970 sea ice dataset, this poses a significant challenge to quantifying the mechanisms responsible for driving such trends. However, historical records from early Antarctic expeditions contain a wealth of information regarding the nature and concentration of sea ice. Such records have been underutilised, and their analysis may enhance our understanding of recent Antarctic sea ice variability. For the purpose of this study, nine records from eight Antarctic expeditions have been examined. Summer sea ice positions recorded during 1820–1843 have been compared to satellite observations from 1987–2017, as well as historical data for the period 1897–1917. Through analysis of these three time series, estimates for the northern limits of summer sea ice in the Weddell Sea during the early 19th century have been produced. The key findings of this study indicate a 19th century average core summer northernmost sea ice latitude in much of the Weddell Sea that was further north than during the modern era, with 19th century February having significantly more sea ice by all measures. However, late summer sea ice was most extensive in the early years of the 20th century.

The “Lund Moraine” – the geomorphic limit of the last Young Baltic ice advance in the Öresund region

ABSTRACT Here we present geomorphological evidence of a previously unrecognised ∼50 km long, ice-marginal moraine complex in southwestern Skåne, southernmost Sweden, which we name the “Lund Moraine”. This lobate moraine marks a sharp boundary between heavily streamlined and gently undulating landscapes, and closely outlines the extent of the “Lund till/diamicton”. We interpret that the moraine was formed by a northward readvance, corresponding to a last Young Baltic readvance of the Scandinavian Ice Sheet into Öresund. Consequently, we infer that the “Lund till/diamicton” was formed subglacially, in contrast to earlier interpretations of it being a waterlain diamicton. Based on previously published dates, stratigraphically below “Lund till/diamicton”, we infer that this readvance occurred sometime after c. 16 cal. ka BP. This readvance could offer an explanation to the apparent discrepancy of observations of the postglacial marine limit from outside and inside the Lund Moraine. Our observations will hopefully settle the ∼50 years long controversy concerning the extent or even existence of such a readvance into Öresund. We expect that our findings will guide further work towards disentangling the complex deglacial history of Skåne and the wider Öresund region.

A Large New Crater Exposes the Limits of Water Ice on Mars

AbstractWater ice in the Martian mid‐latitudes has advanced and retreated in response to variations in the planet's orbit, obliquity, and climate. A 150 m‐diameter new impact crater near 35°N provides the lowest‐latitude impact exposure of subsurface ice on Mars. This is the largest known ice‐exposing crater and provides key constraints on Martian climate history. This crater indicates a regional, relatively pure ice deposit that is unstable and has nearly vanished. In the past, this deposit may have been tens of meters thick and extended equatorward of 35°N. We infer that it is overlain by pore ice emplaced during temporary stable intervals, due to recent climate variability. The marginal survival of ice here suggests that it is near the edge of shallow ice that regularly exchanges with the atmosphere.

Extending the knock limits of hydrogen DI ICE using water injection

This paper presents an experimental and numerical study of a directly-injected, spark ignited, heavy-duty, hydrogen-fuelled engine with boost. Consistent with prior works, engine operation with compression ratios of 12:1 and 14:1 but without water injection are found to be knock-limited at richer conditions, more advanced spark timings, and particularly at the higher compression ratio. Water injection into the intake manifold is then used to suppress autoignition and knock, and thus enable diesel-like power via richer operation at more optimal operating conditions.The dependence of these observed trends on key physical processes is then examined numerically. This includes considering water injection to potentially impact autoignition via three potential routes - a charge cooling effect, a thermophysical effect and a kinetic effect. The impact of charge cooling is found to be dominant, with the thermophysical effect also significant but the kinetic effect weak.

Numerical Calculation Method of Spanwise Icing Characteristics and Performance Loss of Three-Dimensional Vertical Axis Wind Turbine Blades

Most icing studies use 2D or quasi-3D models, ignoring the effects of blade span and tip icing. In this paper, a new model for predicting 3D vertical axis wind turbine blades icing by supplementing the blade span is established, the icing characteristics of blades under multiple working conditions are simulated step by step from the time scale, and the unsteady icing laws are compared and analyzed. Ice properties and surface temperature distribution determine the corresponding deicing power. The analysis results show that the unfrozen water film flows in the spanwise direction of the blade, resulting in a smaller icing limit on the pressure surface than the two-dimensional model, which indicates that the chordwise anti-icing structure can be set in a small range. At the same time, the annular ridge ice formed at the end of the blade slows down the reduction rate of the lift-drag ratio of the blade, effectively reducing the influence of the leading edge ice shape on the aerodynamic performance of the blade. Finally, the critical ice melting power density required to reach equilibrium temperature at the leading edge of the blade is reduced by about 11% compared to the trailing edge due to the increased thermal resistance of the gas-to-blade matrix interface by the ice layer.

Cordilleran Ice Sheet Stability During the Last Deglaciation

AbstractWe report 20 10Be exposure ages from glacial erratics and bedrock on the west coast of British Columbia, Canada, which add to existing chronologies of Cordilleran Ice Sheet retreat along ∼600 km of coastal North America. Collectively, these data show the western ice limit reached the present coast by 18–16 ka then retreat slowed for ∼4,000 years until 14–13 ka. We attribute initial retreat to destabilization and grounding line retreat resulting from rising sea level and/or ocean warming in the northern Pacific. Subsequent stability of the ice sheet at the present coastal margin was likely due to the transition from marine to terrestrial margins despite increasing temperatures that may have driven ice sheet thinning. Our findings demonstrate the importance of understanding both climatic and nonclimatic drivers of ice sheet change through time.

Energy mass balance and flow modeling of early Holocene glaciers in the Queshque valley, Cordillera Blanca, Peru

Our limited knowledge of the timing and pattern of early Holocene climate variability in the tropical Andes hinders our ability to evaluate any potential linkages between low and high latitude oceanic-atmospheric dynamics. There is mounting evidence that glaciers in the Peruvian Andes stabilized at times during the early Holocene, suggesting there were periods of colder and/or wetter conditions that interrupted an overall pattern of a warmer and drier climate. Evaluating the global significance of these glacial fluctuations requires that the nature of these apparent cooling events and any shifts in the hydrologic cycle be better quantified. Here we apply a physically-based glacier model to reconstruct and interpret early Holocene-aged paleoglaciers in steady-state with a range of tropical climatic conditions in the Queshque valley of the Cordillera Blanca, Peru (9.8°S). This model uses a LiDAR-based digital elevation model (DEM) and hourly meteorological data as inputs to calculate the fully-distributed surface energy and mass balance (SEMB). This approach allows us to better capture the diurnal range of environmental variability at a spatial resolution that has not been achieved with previous paleo-glacier modeling efforts in this region. A 3-D rendition of paleoglaciers was then developed based on a flow model that responds to the SEMB input, accounting for the valley topography. The model was validated by simulating glaciers that match both field and satellite observations of modern glacier area limits, as well as ice thicknesses that are consistent with recently measured ground-penetrating radar (GPR) profiles of the main glacier tongue. After adjusting for changes in early Holocene global radiation values, and using regional paleoclimate records as constraints for the model, the maximum early Holocene ice limit in the valley dating to ∼10.8 (±0.1) ka was reconstructed using a 3.0 °C cooling and a 25% increase in precipitation relative to today. An up-valley ice extent dating to ∼9.4 (±0.3) ka was reconstructed using a 2.8 °C cooling and no change in precipitation amounts relative to today. These results suggest that conditions were cold and wet enough to maintain glaciers at times during the early Holocene, even though a shift to drier conditions combined with modestly warmer temperatures drove a phase of ice retreat from at least ∼10.8 to ∼9.4 ka. These results suggest that southern tropical temperatures and the hydrologic cycle rapidly reorganized during the early Holocene in conjunction with diminishing ice sheets and shifting environmental conditions in the high latitudes.

A Wind Tunnel Experimental Study on the Icing Characteristics of a Cylinder Rotating around a Vertical Axis

Rotating machinery in cold and humid regions is prone to icing. For exploring the characteristics of icing on objects rotating around a vertical axis, such as vertical axis wind turbines (VAWT), a cylinder rotating around the vertical axis was selected as the research object in this study. Three cylinders with different diameters were selected, and icing tests carried out under different tip speed ratios (TSR) in a self-built icing wind tunnel. The icing characteristics were quantitatively analyzed using characteristic parameters, including the icing area, the dimensionless icing area, the stagnation point thickness and the dimensionless stagnation point thickness. The dimensionless stagnation point thickness decreased with increases in the diameter of the cylinder. The icing limit decreased with an increase in the rotational speed of the cylinder, and reached 50% under the high TSR condition. Various icing characteristics were also analyzed for two rotation modes: rotation around the vertical axis and around the horizontal axis. The research findings in the present study lay the theoretical and experimental foundations for exploring VAWT icing in depth.

Postglacial sea-level lowstand on Cumberland Peninsula, Baffin Island, Nunavut

This study investigates the postglacial sea-level history of eastern Cumberland Peninsula, a region of Baffin Island, Nunavut, where submerged terraces were documented in the 1970s. The elevation gradient of emerged postglacial marine-limit deltas and fiord-head moraines led Arthur Dyke to propose a conceptual model for continuous postglacial submergence of the eastern peninsula. Multibeam mapping over the past decade has revealed eight unequivocal submerged deltas at 19–45 m below present sea level (b.s.l.) and other relict shore-zone landforms (boulder barricade, spits, and sill platform) at 16–51 m b.s.l. Over a distance of 115 km from Qikiqtarjuaq to Cape Dyer, the submerged coastal features increase in depth toward the east, with a slope (0.36 m/km) less than that of the marine-limit shoreline previously documented (0.58–0.62 m/km). The submerged ice-proximal deltas, deglacial ice limits, and radiocarbon ages constrain the postglacial lowstand between 9.9 and 1.4 ka cal BP. The glacial-isostatic model ICE-7G_NA (VM7) computes a lowstand relative sea level at 8.0 ka, the depth of which increases eastward at 0.28 m/km. The difference between observed and model-derived lowstand depths ranges from 1 m in the west to 10 m in the east and the predicted tilt is significantly less than observed (p = 0.0008). The model results, emerging data on Holocene glacial readvances on eastern Baffin Island, and evidence for proglacial delta formation point to a Cockburn (9.5–8.2 ka) age for the lowstand, most likely later in this range. This study confirms the 1970s conceptual model of postglacial submergence in outer Cumberland Peninsula and provides field evidence for further refinement of glacial-isostatic adjustment models.

Speleothem Records of the Hydroclimate Variability throughout the Last Glacial Cycle from Manita peć Cave (Velebit Mountain, Croatia)

We present stable carbon (δ13C) and oxygen (δ18O) isotope records from two partially coeval speleothems from Manita peć Cave, Croatia. The cave is located close to the Adriatic coast (3.7 km) at an elevation of 570 m a.s.l. The site experienced competing Mediterranean and continental climate influences throughout the last glacial cycle and was situated close to the ice limit during the glacial phases. U-Th dating constrains the growth history from Marine Isotope Stage (MIS) 5 to MIS 3 and the transition from MIS 2 to MIS 1. 14C dating was used to estimate the age of the youngest part of one stalagmite found to be rich in detrital thorium and thus undatable by U-Th. On a millennial scale, δ18O variations partly mimic the Dansgaard–Oeschger interstadials recorded in Greenland ice cores (Greenland Interstadials, GI) from GI 22 to GI 13. We interpret our δ18O record as a proxy for variations in precipitation amount and/or moisture sources, and the δ13C record is interpreted as a proxy for changes in soil bioproductivity. The latter indicates a generally reduced vegetation cover towards MIS 3–MIS 4, with shifts of ~8‰ and approaching values close to those of the host rock. However, even during the coldest phases, when a periglacial setting and enhanced aridity sustained long-residence-time groundwater, carbonic-acid dissolution remains the driving force of the karstification processes. Speleothem morphology follows changes in environmental conditions and complements regional results of submerged speleothems findings. Specifically, narrow sections of light porous spelaean calcite precipitated during the glacial/stadial sea-level lowstands, while the warmer and wetter conditions were marked with compact calcite and hiatuses in submerged speleothems due to sea-level highstands. Presumably, the transformation of this littoral site to a continental one with somewhat higher amounts of orographic precipitation was a site-specific effect that masked regional environmental changes.

UAV icing: the influence of airspeed and chord length on performance degradation

PurposeThe main purpose of this paper is to investigate the effects of icing on unmanned aerial vehicles (UAVs) at low Reynolds numbers and to highlight the differences to icing on manned aircraft at high Reynolds numbers. This paper follows existing research on low Reynolds number effects on ice accretion. This study extends the focus to how variations of airspeed and chord length affect the ice accretions, and aerodynamic performance degradation is investigated.Design/methodology/approachA parametric study with independent variations of airspeed and chord lengths was conducted on a typical UAV airfoil (RG-15) using icing computational fluid dynamic methods. FENSAP-ICE was used to simulate ice shapes and aerodynamic performance penalties. Validation was performed with two experimental ice shapes obtained from a low-speed icing wind tunnel. Three meteorological conditions were chosen to represent the icing typologies of rime, glaze and mixed ice. A parameter study with different chord lengths and airspeeds was then conducted for rime, glaze and mixed icing conditions.FindingsThe simulation results showed that the effect of airspeed variation depended on the ice accretion regime. For rime, it led to a minor increase in ice accretion. For mixed and glaze, the impact on ice geometry and penalties was substantially larger. The variation of chord length had a substantial impact on relative ice thicknesses, ice area, ice limits and performance degradation, independent from the icing regime.Research limitations/implicationsThe implications of this manuscript are relevant for highlighting the differences between icing on manned and unmanned aircraft. Unmanned aircraft are typically smaller and fly slower than manned aircraft. Although previous research has documented the influence of this on the ice accretions, this paper investigates the effect on aerodynamic performance degradation. The findings in this work show that UAVs are more sensitive to icing conditions compared to larger and faster manned aircraft. By consequence, icing conditions are more severe for UAVs.Practical implicationsAtmospheric in-flight icing is a severe risk for fixed-wing UAVs and significantly limits their operational envelope. As UAVs are typically smaller and operate at lower airspeeds compared to manned aircraft, it is important to understand how the differences in airspeed and size affect ice accretion and aerodynamic performance penalties.Originality/valueEarlier work has described the effect of Reynolds number variations on the ice accretion characteristics for UAVs. This work is expanding on those findings by investigating the effect of airspeed and chord length on ice accretion shapes separately. In addition, this study also investigates how these parameters affect aerodynamic performance penalties (lift, drag and stall).

Boundary Conditions for Compressor Cascade Ice Crystal Icing Testing

Abstract At the Altitude Test Facility (ATF) of the University of Stuttgart, a linear compressor cascade test rig serves the investigation of ice crystal icing (ICI) under engine realistic conditions. A numerical model of the first stage of National Aeronautics and Space Administration (NASA) Stage 67 is validated with experimental data taken from the literature and used to investigate the respective ice crystal icing conditions for prospective cascade experiments. Eleven operating points simulating climb conditions with constant non-dimensional power setting through ascending parcels of moist air are selected for analysis. Only the melting-dominated regime is considered. The three-dimensional flow field is obtained using a Reynolds-averaged Navier–Stokes (RANS) approach in combination with a Spalart–Allmaras one-equation turbulence model. The droplet and ice crystal trajectories are calculated based on an Eulerian framework. The computation of the surface energy balance is adapted from the Messinger model taking into account unsteady phenomena. Four of 11 selected operating points indicate the onset of substantial ice accretion. A static wet-bulb temperature of freezing constitutes in general the lower icing limit for rig experiments. The upper icing limit depends on the ice water content impinging and sticking to the target surface.

Radio-echo sounding and waveform modeling reveal abundant marine ice in former rifts and basal crevasses within Crary Ice Rise, Antarctica

AbstractCrary Ice Rise formed after the Ross Ice Shelf re-grounded ~1 kyr BP. We present new ice-penetrating radar data from two systems operating at center frequencies of 7 and 750 MHz that confirm the ice rise is composed of a former ice shelf buried by subsequent accumulation. Stacks of englacial diffraction hyperbolas are present almost everywhere across the central ice rise and extend up to ~350 m above the bed. In many cases, bed reflections beneath the diffraction hyperbolas are obscured for distances up to 1 km. Waveform modeling indicates that the diffraction hyperbolas are likely caused by marine ice deposits in former basal crevasses and rifts. The in-filling of rifts and basal crevasses may have strengthened the connection between the ice rise and the surrounding ice shelf, which could have influenced local and regional ice dynamics. Three internal reflection horizons mark the upper limit of disturbed ice and diffraction hyperbolas in different sections of the ice rise, indicating at least three stages of flow stabilization across the ice rise. A surface lineation visible in MODIS imagery corresponds spatially to deepening and strong deformation of these layers, consistent with the characteristics of former grounding lines observed elsewhere in Antarctica.

Luminescence dating of a late Middle Pleistocene glacial advance in eastern England

Abstract Previous investigation of isolated landforms, on the eastern margin of the East Anglian Fenland, England, has demonstrated that they represent an ice-marginal delta and alluvial fan complex deposited at the margin of an ice lobe that entered the Fenland during the ‘Tottenhill glaciation’ (termed the ‘Skertchly Line’). They have been attributed, based on regional correlations, to a glaciation during the Late Wolstonian (i.e. Late Saalian) Substage (Drenthe Stadial, early Marine Isotope Stage (MIS) 6). This paper aimed to test this correlation by directly optically luminescence dating, for the first time, sediments found within the Skertchly Line at Shouldham Thorpe, Norfolk, and Maidscross Hill, Suffolk, together with those in associated kame terrace deposits at Watlington, Norfolk. Ages ranged from 244 ± 10 ka to 12.8 ± 0.46 ka, all the results being younger than MIS 8 with some clearly showing the landforms have been subsequently subjected to periglacial processes, particularly during the Late Devensian Substage (∼MIS 2). Most of the remainder fall within the range 169–212 ka and could be assigned to MIS 6, thus confirming the previously proposed age of the glaciation. The local and regional implications of these conclusions are discussed, the maximum ice limit being linked to that of the Amersfoort–Nijmegen glaciotectonic ridge limit in the central Netherlands.

Use of remote sensing results in the tasks of navigational and hydrographic situation monitoring

The paper presents the possibilities of using modern online sources of satellite information in the tasks of monitoring the ecological and navigational-hydrographic situation and building on their basis methods and information technologies to reflect the state of marine waters and operational forecasting of changes in this state. For the tasks of monitoring the ecological and navigational-hydrographic situation, one of the most convenient and informative is the marine environment monitoring service COPERNICUS (CMEMS). This service collects and presents data on observations of spatio-temporal variability of sea water temperature and salinity values, streams parameters, etc. by using specialized artificial satellites Sentinel-1 and Sentinel-2, which intended for use in the mission of a dual satellite with high viewing frequency and high resolution. CMEMS provides, on a regular and systematic basis, information on the physical condition, variability and dynamics of the oceanic and marine ecosystems. The principle of measurement uses natural microwave emissions on the sea surface, which vary depending on the degree of roughness of the sea surface. You can get the parameters of wind direction, atmospheric water vapor, rain speed, sea ice (age, concentration and limit), the length of the snow cover and the water content in the snow. High-resolution ice mapping services provide ice classification and floating ice data to navies and shipping companies to ensure safe year-round shipping. The ability of the Sentinel-1 to conduct observations in any weather and during the day or night makes it ideal for accurately determining the location and movement of the vessel at sea. Oil detection applications are used to gather evidence of illegal discharges, analyze the spread of oil spills and search for oil reserves by detecting natural infiltration. Sentinel-1 marine products, in combination with global sea wave models, help determine the direction, wavelength and height of waves on the open sea, as well as help predict the weather, the movement of ships and the use of wave energy. In addition, Sentinel-1 can provide data on the interaction of ocean waves and streams, which allows you to visualize large-scale ocean streams, cold/warm water massifs, coastal streams and internal waves. Software and hardware complexes and information-analytical systems created with the use of these methods and technologies can significantly increase the efficiency and effectiveness of solving problems of environmental monitoring, navigation and hydrographic support of navigation, search and rescue operations in marine waters.

Age-estimate evidence for a complex Middle to Late Pleistocene fluvial terrace aggradation spanning more than a 100-kyr interglacial–glacial cycle at Sutton Cross, eastern England

At Sutton Cross, eastern England, an undated River Nene 2nd Terrace was known to record a complex sequence of late Middle to Upper Pleistocene deposits. Amino acid geochronology was carried out for samples from four separate facies associations in order to provide a chronostratigraphic framework for this complex deposit. Each sample comprised three specimens of Bithynia tentaculata opercula. The intracrystalline protein decomposition results confirmed the sedimentary stratigraphic interpretation previously proposed for the site, i.e., that fossiliferous sediments yielding fully temperate Mollusca and Ostracoda faunas are equivalent in age to marine isotope stage (MIS) 7. Palaeotemperature reconstructions based on the Ostracoda fauna (July: +14 to +26 °C; January: −4 to +5/+3 °C) embrace those of today at this location (July: +17 °C; January +3 °C). The sedimentary succession at Sutton Cross comprises vertically aggraded packages with a probable maximum age of MIS 8 and minimum age of MIS 2. This aggradation pattern (and age range) is also common to downstream sedimentary successions at Whittlesey, and is counterintuitive to the traditional terrace stratigraphy approach that expects laterally aggrading downstepping packages. The preservation of sediments of MIS 7 age and older at Sutton Cross with no evidence of glacial overriding places constraints on recently proposed late Middle Pleistocene regional ice limits.

In-flight icing simulation for two-dimensional configurations

This paper presents a comprehensive aircraft icing simulation tool implemented in an in-house Navier–Stokes parallel multi-block solver. In detail, the droplet flow field is solved by Eulerian approach, and a Partial Differential Equation (PDE)-based ice accretion model is adopted to determine the runback water flow and icing rate. Numerical validations are performed on the two-dimensional (2D) NACA 0012 airfoil, where good agreements with the literature are observed. Additionally, the paper investigates the influence of droplet size on the final ice shape. Results show that droplets with greater Median Volume Diameter (MVD) are more likely to impact on the wall, which results in larger droplet impingement limit and icing limit.

Refining the history of Younger Dryas and Early Holocene glacier oscillations in the Borgarfjörður region, western Iceland

The lower Borgarfjörður region, western Iceland, has been central to the reconstructions of the dynamics and collapse of the Icelandic Ice Sheet during the deglaciation. Here, extensive stratigraphical sections and landforms provide a rare opportunity to study past glacier dynamics in this part of Iceland. Previous studies reveal that a large outlet glacier in Borgarfjörður advanced during the Late Weichselian resulting in large‐scale deformation of glaciomarine sediments and the formation of a series of ice‐marginal moraines. However, the events recorded by these sediments and landforms are poorly constrained in time. We present and discuss 22 new radiocarbon dates in the context of recent reconstructions of the regional glacier dynamics in order to constrain the timing of the glacier oscillations. The results show that a dynamic, marine‐terminating glacier advanced out of Borgarfjörður sometime after c. 13.0 cal. ka BP, resulting in the formation of an extensive moraine complex. The timing indicates that the advance occurred during climate cooling and widespread glacier expansions within the Younger Dryas. Followed by the first initial advance, the glacier exhibited at least five re‐advances punctuated by phases of retreat. Each re‐advance terminated proximal (within 5 km) to the outermost moraine complex although the extent of periodic retreat and the exact timing of these oscillations are unknown. All these phases of re‐advance occurred prior to the onset of the Holocene (around 11.7 cal. ka BP), during which marine fauna re‐colonized the area and the Borgarfjörður glacier retreated from the moraines. During the Early Holocene (sometime after c. 11.3 cal. ka BP), the Borgarfjörður glacier re‐advanced to a position within ~5 km of the YD ice limit. This is the first recorded Early Holocene large‐scale glacier advance in western Iceland and suggests that glacier expansion in this region coincided with widespread advances elsewhere in Iceland.