Ice-free Lake Research Articles

Evaporation over a glacial lake in Antarctica

Abstract. The study provides estimates of summertime evaporation over a glacial lake located in the Schirmacher oasis, Dronning Maud Land, East Antarctica. Lake Zub (alternately named Lake Priyadarshini and referred to throughout as Lake Zub/Priyadarshini) is the second-largest lake in the oasis, and its maximum depth is 6 m. The lake is also among the warmest glacial lakes in the oasis, and it is free of ice during almost 2 summer months. The summertime evaporation over the ice-free lake was measured using the eddy covariance method and estimated on the basis of five indirect methods (bulk-aerodynamic method and four combination equations). We used meteorological and hydrological measurements collected during a field experiment carried out in 2018. The eddy covariance method was considered the most accurate, and the evaporation was estimated to be 114 mm for the period from 1 January to 7 February 2018 (38 d) on the basis of this method. The average daily evaporation was 3.0 mm d−1 in January 2018. During the experiment period, the largest changes in daily evaporation were driven by synoptic-scale atmospheric processes rather than local katabatic winds. The bulk-aerodynamic method suggests the average daily evaporation is 2.0 mm d−1, which is 32 % less than the results based on the eddy covariance method. The bulk-aerodynamic method is much better in producing the day-to-day variations in evaporation compared to the combination equations. All selected combination equations underestimated the evaporation over the lake by 40 %–72 %. The scope of the uncertainties inherent in the indirect methods does not allow us to apply them to estimate the daily evaporation over Lake Zub/Priyadarshini. We suggested a new combination equation to evaluate the summertime evaporation over the lake's surface using meteorological observations from the nearest site. The performance of the new equation is better than the performance of the indirect methods considered. With this equation, the evaporation over the period of the experiment was 124 mm, which is only 9 % larger than the result according to the eddy covariance method.

Environmental Changes and Geomorphological Factors Influencing the Sediment Flux to a Coastal Lake Spanning the Deglacial- Early Holocene Period in East Antarctica

Abstract The geomorphological settings of the lakes in the coastal oases of East Antarctica play a significant role in the lake's response to the local and regional environment. A 63-cm radiocarbon-dated sediment core spanning between 18.7 and 7.2 cal ka BP was retrieved from Discussion Lake, Larsemann Hills of East Antarctica in order to understand the pathways of sediment transport and deposition and the mechanisms involved in response to changing environmental settings. This was achieved by analyzing the sedimentary sequence of this coastal lake for its grain size (sand-silt-clay) and organic matter content variations. Two cluster zones were identified viz., LZ1 (18.7 to 8.2 cal ka BP) and LZ2 (8.2 to 7.7 cal ka BP). LZ1 was dominated by fine-grained sediments (clay-silt), indicating wind and low meltwater influx influenced deposition of higher silt content. In addition, the lake during this period was in a moated or partially ice-free phases. On the other hand, coarser grains (sand) were predominant in LZ2 suggesting increased flux of the meltwater to the ice-free lake. Thus, the distinct shift in the sedimentary grains fractions (finer-to-coarser), indicated a change in environmental conditions of the lacustrine system, i.e., from an ice-covered lake to an ice-free lake in response to the regional warming trends and local geomorphological features. Furthermore, the environmental conditions, proximity of the lakes to coast or the ice-sheet, elevation and area, defines the sedimentological characteristics of the lake.

Technical note: Mobile open dynamic chamber measurement of methane macroseeps in lakes

Abstract. Methane (CH4) seepage (i.e., steady or episodic flow of gaseous hydrocarbons from subsurface reservoirs) has been identified as a significant source of atmospheric CH4. However, radiocarbon data from polar ice cores have recently brought into question the magnitude of fossil CH4 seepage naturally occurring. In northern high latitudes, seepage of subsurface CH4 is impeded by permafrost and glaciers, which are under an increasing risk of thawing and melting in a globally warming world, implying the potential release of large stores of CH4 in the future. Resolution of these important questions requires a better constraint and monitoring of actual emissions from seepage areas. The measurement of these seeps is challenging, particularly in aquatic environments, because they involve large and irregular gas flow rates, unevenly distributed both spatially and temporally. Large macroseeps are particularly difficult to measure due to a lack of lightweight, inexpensive methods that can be deployed in remote Arctic environments. Here, we report the use of a mobile chamber for measuring emissions at the surface of ice-free lakes subject to intense CH4 macroseepage. Tested in a remote Alaskan lake, the method was validated for the measurement of fossil CH4 emissions of up to 1.08 × 104 g CH4 m−2 d−1 (13.0 L m−2 min−1 of 83.4 % CH4 bubbles), which is within the range of global fossil methane seepage and several orders of magnitude above standard ecological emissions from lakes. In addition, this method allows for low diffusive flux measurements. Thus, the mobile chamber approach presented here covers the entire magnitude range of CH4 emissions currently identified, from those standardly observed in lakes to intense macroseeps, with a single apparatus of moderate cost.

A study of Lake Erie seiche and low frequency water level fluctuations in the presence of surface ice

Coastal storms can initiate periodic low-frequency fluctuations of water level particularly in enclosed bodies of water. Such oscillations, known as seiches, can potentially result in an unexpected rise in water level leading to coastal flooding in low lying areas. Low frequency water level motions are also believed to contribute to long-term erosion of coasts. In this paper, low frequency motions of Lake Erie water levels are, analytically and numerically, studied for ice-free and ice-covered lake conditions. For the analytical study, first, a spectral analysis is performed on long-term hourly water level data collected over a 40-year period (1975–2015) at various water levels measuring stations around the lake. The frequencies of the lake's seiching modes are determined and the spatial variations of the energy corresponding to the low frequency fluctuations of the lake are investigated. Secondly, the seasonal variations of the seiching motions as well as the effects of surface ice on the low frequency oscillations of the lake level are assessed by analyzing the spectra and cross-spectra of the hourly water level data at various stations during winter and summer for ice-covered and ice-free conditions. The spatial variations of the spectral energy, phase lag and coherence for the low frequency motions are quantified for the winter and summer data. The lake's low frequency water level variations for a short-term extreme event, i.e. storm, are studied numerically. A historical winter storm taking place under ice-covered lake conditions is simulated using a coupled storm surge and spectral wave model (ADCIRC-SWAN). The model is forced by wind and pressure fields under a hypothetical ice-free conditions. The spectra of the low frequency motions for the simulated and measured lake level time-series are then compared. The spectral analysis of the Lake Erie long-term hourly water level data reveals distinct energy concentrations at the frequencies of approximately 1.7, 2.6, 4.1 and 5.8 cycle/day (CPD) which correspond to the first four modes of seiching oscillations. The energy corresponding to the low frequency motions is found to be at its highest level near Toledo, in the western basin, and lowest in Fairport, located at the nodal point for the first mode. The comparisons of the summer and winter spectra show that surface ice can suppress the low frequency oscillations. In general, the spectra of the lake levels during the summer are more peaked at the seiching modes than those of the winters when the lake is ice-covered. For the low frequency oscillations of the lake level following a short-term extreme event, higher energy levels are associated with the ice-free lake condition. This energy level is higher at the eastern and western ends of the lake, consistent with the findings for the winter and summer lake level oscillations. In general, the effect of surface ice on low frequency fluctuations of the lake is more pronounced in the western basin where typically more extensive surface ice is present during winters.

Impact of partly ice-free Lake Ladoga on temperature and cloudiness in an anticyclonic winter situation – a case study using a limited area model

At the end of January 2012, a low-level cloud from partly ice-free Lake Ladoga caused very variable 2-m temperatures in Eastern Finland. The sensitivity of the High Resolution Limited Area Model (HIRLAM) to the lake surface conditions was tested in this winter anticyclonic situation. The lake appeared to be (incorrectly) totally covered by ice when the lake surface was described with its climatology. Both parametrisation of the lake surface state by using a lake model integrated to the NWP system and objective analysis based on satellite observations independently resulted in a correct description of the partly ice-free Lake Ladoga. In these cases, HIRLAM model forecasts were able to predict cloud formation and its movement as well as 2-m temperature variations in a realistic way. Three main conclusions were drawn. First, HIRLAM could predict the effect of Lake Ladoga on local weather, when the lake surface state was known. Second, the current parametrisation methods of air–surface interactions led to a reliable result in conditions where the different physical processes (local surface processes, radiation and turbulence) were not strong, but their combined effect was important. Third, these results encourage work for a better description of the lake surface state in NWP models by fully utilising satellite observations, combined with advanced lake parametrisation and data assimilation methods.

Interactive lakes in the Canadian Regional Climate Model, version 5: the role of lakes in the regional climate of North America

ABSTRACTTwo one-dimensional (1-D) column lake models have been coupled interactively with a developmental version of the Canadian Regional Climate Model. Multidecadal reanalyses-driven simulations with and without lakes revealed the systematic biases of the model and the impact of lakes on the simulated North American climate.The presence of lakes strongly influences the climate of the lake-rich region of the Canadian Shield. Due to their large thermal inertia, lakes act to dampen the diurnal and seasonal cycle of low-level air temperature. In late autumn and winter, ice-free lakes induce large sensible and latent heat fluxes, resulting in a strong enhancement of precipitation downstream of the Laurentian Great Lakes, which is referred to as the snow belt.The FLake (FL) and Hostetler (HL) lake models perform adequately for small subgrid-scale lakes and for large resolved lakes with shallow depth, located in temperate or warm climatic regions. Both lake models exhibit specific strengths and weaknesses. For example, HL simulates too rapid spring warming and too warm surface temperature, especially in large and deep lakes; FL tends to damp the diurnal cycle of surface temperature. An adaptation of 1-D lake models might be required for an adequate simulation of large and deep lakes.

Small freshwater thalassiosiroid diatoms from Pleistocene sediments of Pingualuit Crater Lake, northern Québec (Canada), including description of Cyclotella pingualuitii sp. nov.

Arctic and sub-arctic lake sediment sequences from the Pleistocene are uncommon due to multiple glacial–interglacial cycles and the associated advances and retreats of Pleistocene ice sheets. Pleistocene strata are preserved in a 9-m-long sediment core recovered from Pingualuit Crater Lake, Nunavik, northern Québec (Canada). In addition to tychoplanktonic Aulacoseira species, the Pleistocene planktonic flora comprises representatives from the thalassiosiroid genera Cyclotella, Discostella and Puncticulata, of which most species are extant in perennially ice-free sub-arctic and arctic lakes. One Cyclotella species, C. pingualuitii is described as new and is characterized by a small central area, multiple central and scattered marginal fultoportulae with triangular satellite pore covers, a single large submarginal rimoportula and alveolate striae of unequal length. Cyclotella pingualuitii is the most prominent species during the oldest diatom-rich interval (DR3) recovered, which was deposited during the Late Quaternary (29–36 ky bp). This species has not been observed above 400 cm in Pingualuit Crater Lake sediments, or elsewhere in Pleistocene or Holocene sequences or modern collections, and is considered extinct.

Effect of solar radiation on photosynthetic extracellular carbon release and its microbial utilization in alpine and Arctic lakes

The effect of solar radiation (photosynthetically active radiation and ultraviolet radiation (UVR)) on the photosynthetic extracellular release (PER) of phytoplankton and its utilization by bacterioplankton were studied in an alpine lake (Gossenkollesee, Austria) over a seasonal cycle. For comparison, 2 Arctic lakes on the Taymir Peninsula (Siberia) were investigated as well. The contribution of PER to primary production (% net PER) ranged between 0 and 95% (mean 32%) in Gossenkollesee (May 1999 to July 2000) following a seasonal trend that was inversely related to phytoplankton biomass. PER was released only under light conditions and was positively related to the intensity of solar radiation. During the ice-covered period, the % net PER increased, while total primary production (Ptot) decreased with experimentally increasing irradiance, indicating radiation- induced stress with dark-adapted phytoplankton. During the ice-free period, the increase of % net PER with increasing irradiance was independent of photoinhibition. The fraction of PER not immedi- ately incorporated by bacteria (~60% of total PER) may be an important contribution to the generally low pool of dissolved organic carbon (DOC) in Gossenkollesee. At the Arctic site, net PER amounted to 21% of Ptot in an ice-free lake and 51% in the ice-covered Lake Nyagamya. In all lakes, the amount of PER was sufficient to meet the bacterial carbon demand. The UVR-induced inhibition of primary production in the investigated lakes was inversely related to the DOC concentration of the water column, with the lowest effect in the ice-free Arctic lake (3.5% reduction of Ptot) and the highest impact in the alpine lake (56% reduction of Ptot, 61% reduction of PER); the percentage of net PER was apparently not controlled by UVR. This suggests that the investigated alpine lake is more sensitive to changes in UVR than the Arctic lakes are.

Ecological processes in Antarctic inland waters: interactions between physical processes and the nitrogen cycle

AbstractIn this review we consider the physical processes that shape inland aquatic ecosystems and how these affect ecosystem processes, with particular focus on the nitrogen cycle. Inland Antarctica is dominated by microbial communities that are usually concentrated in, or adjacent to, habitats with free water. The presence of free vs frozen water is dependent on very small changes in temperature around 0°C, so significant variability in the distribution of free water can be expected in response to variations in climate over diel, decadal, to millennial time scales and a range of spatial scales. Antarctic inland waters take many forms: snow-surface melt pockets, cryoconites, basal regions of wet-based glaciers, ponds (varying in salinity and degree of desiccation), melt streams, perennially and seasonally ice covered lakes and even hypersaline, ice free lakes. The important processes and transformations that characterize the nitrogen cycle worldwide have all been identified in Antarctic inland waters and in some cases (e.g. N-uptake, N-fixation), rates are similar to those at lower latitudes. The unique features of Antarctic ecosystems stem from the extreme and variable physical conditions under which these processes operate rather than any unique ecosystem processes per se.

Lateglacial nunataks in central Scandinavia: Biostratigraphical evidence for ice thickness from Lake Flåfattjønn, Tynset, Norway

This study reveals for the first time biostratigraphical evidence of nunataks emerging from the Late Weichselian ice-sheet in central Scandinavia. Almost 1 m of minerogenic basal layers from Lake Flåfattjønn, 1110 m a.s.l., at Tynset, Norway, was deposited in the Lateglacial, possibly as early as 16,000 cal. yr BP. The sediments contain well-preserved remains of plants, diatoms and chironomids and indicate: (1) a mosaic pioneer vegetation of dwarf-shrub tundra, snow bed vegetation and xerophytes on wind-blown ridges, (2) an ice-free lake during summers with clear water at low pH due to little inwash, (3) a continental climate with summers slightly warmer than today (ca 10 °C), and most probably with very cold winters, according to indications of permafrost, and (4) a hiatus/reduced sedimentation during at least the first half of the Younger Dryas when the lake was sealed by a more-or-less permanent ice-cover. The existence of Lateglacial nunataks indicates a thin and multi-domed Lateglacial ice-sheet in Scandinavia. Early migration of arctic-alpine plants to nunataks could explain their centric distribution in S Norway. Furthermore, vegetation establishment on the Flåfatet Lateglacial nunatak indicates that S Norway could have been vegetated by successions along the retreating ice from alpine nunataks and from coastal and southern areas. The upland and lowland vegetation met at the final deglaciation.

Modeling 50 years of historical temperature profiles in a large central European lake

A unique data set of 50 years of monthly temperature profiles from Lake Zurich, a normally ice‐free lake located on the Swiss Plateau, allowed the one‐dimensional numerical k‐Ε lake model “SIMSTRAT” to be calibrated (1948—1957) and validated (1958—1997). Hindcasts of temperature profiles agree excellently with the measured data. Both interannual and intraannual variations in thermal structure are reproduced well during the entire 50‐yr simulation, thus demonstrating the stability and good prognostic qualities of the model. Simulations conducted with raised and lowered air temperatures (Tair) suggest that an increase in Tair will lead to an increase in lake water temperature at all depths. In comparison to the continuous modeling approach taken in this study, the commonly employed discontinuous modeling approach (with no heat carryover during winter) substantially underestimated the degree of long‐term hypolimnetic warming that can be expected to result from an increase in Tair. Thus, whereas the discontinuous approach yields valid predictions for strictly dimictic lakes that are ice‐covered each winter, heat carryover during winter makes a continuous approach necessary in lakes like Lake Zurich that are only facultatively dimictic. The significant degree of hypolimnetic warming found in this study suggests that the response of facultatively dimictic lakes to increases in Tair is likely to differ from that of the strictly dimictic lakes modeled in other investigations. In Lake Zurich, an increase in Tair is predicted to result in more frequent suppression of deeply penetrative winter mixing events, with a potentially negative impact on the lake ecosystem.

Determining the date of ice-melt for low Arctic lakes along Søndre Strømfjord, southern West Greenland

The length of ice cover has considerable influence on the functioning of lake ecosystems, particularly so in continental and high-latitude regions where lakes freeze annually. Long-term trends in the length of ice cover and the date of ice break-up can be related to regional weather patterns, such as the North Atlantic Oscillation. It is this relationship to weather patterns that has generated considerable interest in the use of long-term icerecords as climate proxies. Although it is reasonable to assume a relationship between the length of the icefree period and lake productivity, it is unclear if this relationship influences the sedimentary record. Whether these ice-climate interactions can be identified in the sediment record is important for distinguishing long-term palaeoclimatic trends from variations in the sediment record (Anderson et al. 2000).

Dispersion in Ice-Covered Lakes

Dispersion studies in three ice-covered lakes are presented. One of the lakes has a large river through-flow. In the other two lakes, small seiche-induced currents are generated through wind action on the ice cover. Dispersion coefficients are computed from five dye experiments lasting from ½ day to 16 days. These coefficients are related to measured current velocities. The turbulence in the river-flow dominated lake is found to be very low with disperision coefficients less than 1 cm2/s in directions transverse to the flow. In the lakes where the turbulence is generated by shear from the seiche-induced currents the horizontal dispersion coefficients are two orders of magnitude higher, being almost as high as in ice-free lakes.

Dispersion in Ice-Covered Lakes

Dispersion studies in three ice-covered lakes are presented. One of the lakes has a large river through-flow. In the other two lakes, small seiche-induced currents are generated through wind action on the ice cover. Dispersion coefficients are computed from five dye experiments lasting from ½ day to 16 days. These coefficients are related to measured current velocities. The turbulence in the river-flow dominated lake is found to be very low with disperision coefficients less than 1 cm2/s in directions transverse to the flow. In the lakes where the turbulence is generated by shear from the seiche-induced currents the horizontal dispersion coefficients are two orders of magnitude higher, being almost as high as in ice-free lakes.

Hydrogeochemical methods for base metal exploration in the northern Canadian shield

The use of lake waters for base metal exploration has been studied in the northern part of the Slave Geological Province of the Canadian Shield. The area is north of the treeline, within the zone of continuous permafrost, and, like most other regions of the Shield, has a high density of small lakes. A regional sampling of 1218 lakes established that less than 2 ppb (μg/l) Zn or Cu is typical of waters from unmineralized terrane. These samples had a median pH of 6.8 and a median specific conductivity of 19.5 μmhos. Lake waters were also taken from the areas surrounding five massive sulphide occurrences: High Lake, Canoe Lake, Takiyuak Lake, Hackett River and Agricola Lake. In all cases there are unambiguous anomalies for Zn. Anomalies are also present for Cu, but are less intense and extensive. This difference between the two elements is related to the superior mobility of Zn in surface waters and its more consistent presence as a major constituent of massive sulphides. A water sampling apparatus has been developed and tested on a light turbine helicopter. Using this, thirty sites may be sampled each hour when sampling at a density of 1 site per 2.8 km2. Measurement of pH, conductivity and water temperature are recorded in the helicopter during sampling. A number of factors have been investigated that may influence the utility of lake water sampling for base metal exploration: (1) Seasonal variability, while present to moderate degree, is unlikely to hinder application of the method. (2) For the size of lakes sampled (2 km2 or less), elements are homogeneously distributed across the lake surface during the ice-free season. During the initial period of break-up there are marked variations in element content around the ice-free lake margin. Sampling during this period may help define the source of metals for anomalous lakes. (3) Study of sample preservation suggests that mobile elements, such as Zn, that are stable in solution within lakes, are also relatively stable when untreated water is stored in plastic bottles. (4) Care must be taken to avoid contamination of the samples, particularly from the bottle. The areal extent of lake water base metal anomalies appears to be less than equivalent lake sediment anomalies. Thus for wide-interval, regional geochemical reconnaissance, lake sediment sampling is the method of choice. Lake waters are an appropriate medium for detailed exploration of areas of interest, such as volcanic belts. For this application, the principal attractions are rapid sampling rates, and hence low costs, high contrast anomalies, and a uniform sampling medium.

Seasonal variations of helium, radon, and uranium in lake waters near the Key Lake uranium deposit, Saskatchewan

Abstract To test the usefulness of the He method for the detection of buried U ore, a lake-water survey of the Key Lake area was carried out during March 1977 and repeated in June 1977. A set of 87 lake-water samples from 37 sites in eight different lakes were collected from the same sites in each survey. These samples were analyzed for He, Rn, O 2 , Eh, pH, conductivity, alkalinity, and U. In the lakes the highest He concentrations, of nearly four times atmospheric equilibrium concentrations, were obtained during the winter survey. This was under the ice in two bottom lake samples where the sandy overburden extends for some 50 m directly to the ore zone. Radon and U values at these sites were also anomalous, but the highest values of Rn and U were obtained in a shallow lake about 2 km south of the ore zone where concentrations of radioactive boulders occur. The average net He and Rn contents dropped from 21 standard nanolitres/litre (nl/l) and 25 picocuries/litre (pCi/l) in the winter under the ice to 3 nl/l and 8 pCi/l in the summer, respectively. Average U and conductivity dropped from 2.3 ppb and 15 μmho/cm to 1.5 ppb and 11 μmho/cm, respectively, in the same suites of samples. The drop in the ionic species probably reflects the effect of snow and ice meltwater dilution and the much larger drop in the dissolved He and Rn reflects the combined effects of meltwater dilution, wind turbulence over ice-free lakes, and change in thermal gradients. The He results must be viewed with guarded optimism until a detailed investigation is completed to ascertain what fraction of the detected He is from the ore, what fraction from basement He that may have found its way into the lakes via the fracture zone in which the ore is located, and what effect drilling has had on the He flow into the lakes from the ore zone.

Seiches, Circulation, and Storm Surges of an Ice-Free Lake Winnipeg

Predictions of numerical hydrodynamical models of seiches, steady circulation, and water level setup and time-dependent motions known as storm surges are compared to limited amounts of water level data during the ice-free season on Lake Winnipeg. Two-dimensional gravitational seiches are computed by minimizing an expression for the total energy. The fundamental inviscid period is 39 h which is considered to be a maximum for any inland water body. Four higher modes of oscillation have been detected in spectra of water level fluctuations at three stations on Lake Winnipeg. Frictional effects are shown to have appreciable influences on the seiches. Predicted water level setup has an asymmetrical distribution with the largest excursions occurring in the southern basin. A number of observations of water level setup are in accordance with model predictions at Winnipeg Beach if a drag coefficient of 1.0 × 10−3 is assumed. Setup is relatively insensitive to vertical eddy diffusivities in the range 10–100 cm2/s. A modeling strategy utilizing the previously obtained solutions for the free oscillations and for the steady state setup results in a simple prediction scheme for arbitrary forcing in time involving the convolution of the time history of the wind stress components with the response of the lake. Predicted storm surges are in reasonable agreement with two storm surges measured at two locations in the southern basin, considering the imperfect knowledge of the forcing obtained from winds at a single station in the northern basin.

The palynology and palaeoclimatic significance of a dated core of Holocene peat, Okanagan Valley, southern British Columbia

Holocene vegetation and climatic changes of the Okanagan Valley, British Columbia, are inferred from fossil pollen assemblages recovered from Kelowna Bog in the central part of the valley. Broad climatic changes inferred from relict postglacial landforms in the valley are correlated with the above changes.The Okanagan Valley was ice-free and Glacial Lake Penticton drained before 8900 yr BP. A forest consisting mainly of pine (Pinus) and stands of spruce (Picea) had colonized the valley sides prior to draining of the lake. Soon after 8400 yr BP, moist conditions gave way to aridity during which grass (Gramineae) and sagebrush (Artemisia) predominated. This warm, dry interval is correlated with the Hypsithermal. Bare areas in the valley bottom were exposed to wind erosion; sand dunes formed in some areas, whereas in others, a veneer of aeolian sediment was laid down. At approximately 6600 yr BP, the climate became cooler and moister, aeolian activity diminished, and the dunes became stabilized by vegetation. During the ensuing latest climatic interval, three moister phases affected Kelowna Bog and were characterized by large increases in birch (Betula), alder (Alnus), and hazel (Corylus). These phases, which were related to increased runoff from the adjacent uplands, are tentatively correlated with the stades of the Neoglaciation recognized in southcentral British Columbia and neighbouring United States.

GEOLOGIC RECONNAISSANCE OF THE EASTERN PART OF THE MOUNTAINS IN QUEEN MAUD LAND, ANTARCTICA

This reports on a four-man geologic reconnaissance of the eastern part of the mountains of Queen Maud Land, Anarctica. The German “Schwabenland” expedition of 1938-1939 had previously reported the so-called “oases” of ice-free lakes and dry land in the area. A description of the physiography and glaciology of the area includes a description of ice-character, fissures, heights of shelf and continental ice fields, and the nature of the coastlines. The “oases” include bedrock rolling lowlands, a nunatak zone, and block mountains. The geologic structure exhibits fault systems, block mountains, and some folding. Igneous and metamorphic rocks occur but no sedimentaries. Speculation on the development of known and probable mineral occurrences concludes that no great transportation difficulties would arise in mining and shipping ores. D. C. Alverson