Giant Iceberg Research Articles

Collapse of a giant iceberg in a dynamic Southern Ocean marine ecosystem: In situ observations of A-68A at South Georgia

Large icebergs (>20 km long) are responsible for most of the freshwater discharged into the Southern Ocean. We report on in situ and satellite observations made during the break-up phase around South Georgia of the giant tabular iceberg A-68A. The in situ measurements were obtained during a 4-day visit by a research vessel in February 2021, where physical, chemical and biological measurements were made at a range of distances away from the main and subsidiary icebergs. These results were compared to a far-field station 133 km away. Upstream of the iceberg field, water column structure was similar to ambient water although there was evidence of iceberg-associated phytoplankton as a likely remnant of the passage of the icebergs. Nevertheless, enhancement of primary productivity along the path of the icebergs was not resolved in either in situ or monthly mean satellite observations. There was a considerable brash-ice field moving ahead of the icebergs which limited the number of downstream sampling stations. One downstream station within 2 km of iceberg A-68P showed several ice-melt influenced features that distinguished it from most other stations. Firstly, there was a strong stratified meltwater influenced layer that reached to around 120 m. This had the effect of deepening underlying water masses, with the core of the temperature minimum layer around 50 m deeper than elsewhere. Secondly, there was evidence of rapid downward displacement of both particulate material and certain phytoplankton taxa that may be a further result of this water mass deepening. Thirdly, macronutrient profiles were altered, with concentrations of nitrate, silicic acid and phosphate characteristic of deeper layers being found closer to the surface and a dilution of the ambient nutrient pool just above the iceberg draft that we ascribe to meltwater released from basal melting. Meanwhile, nutrient recycling processes associated with organic matter remineralisation were also modified by the physical restructuring of the water column and biotic components. Finally, the ice-associated phytoplankton taxa Pseudo-nitszchia/Nitszchia, found in both upstream and downstream locations, were abundant at this < 2 km-distant station through melting out from the iceberg and subsequent rapid growth. Overall, we resolved alterations to water column structure, nutrient profiles and phytoplankton community composition at fine to medium scales around the iceberg field. Nevertheless, although there may have been longer term and larger scale impacts, the dynamic oceanographic environment, including the presence of a strong oceanographic front and shelf-edge processes, dominated during the collapse of A-68A.

Impact of Giant Iceberg A68A on the Physical Conditions of the Surface South Atlantic, Derived Using Remote Sensing

AbstractGiant icebergs release cold, fresh meltwater as they drift, perturbing the physical conditions of the surface ocean. This study uses satellite‐derived sea surface salinity and temperature measurements to explore the physical impact of supergiant iceberg A68A between September 2020 and June 2021. During A68A's drift through the Scotia Sea in austral spring, gradual but persistent edge‐wasting contributed to a freshening of several psu extending hundreds of kilometers ahead of the iceberg, whilst the cooling signal was more pronounced in the iceberg's wake. The magnitude of the physical perturbation intensified during A68A's breakup near South Georgia. Several large meltwater lenses surrounding the descendant icebergs displayed temperature anomalies of up to −4.5°C, whilst the salinity measurements indicated a surface (skin‐depth) anomaly regularly exceeding order −10 psu. The perturbations stretched at times &gt;1,000 km and persisted for &gt;2 months following A68A's melt in April 2021.

The history of a cluster of large icebergs on leaving the Weddell Sea pack ice and their impact on the ocean

AbstractThe life history and oceanic impact of three very large icebergs that escaped together from the Weddell Sea sea ice, near the tip of the Antarctic Peninsula, are traced from March 2014. Despite the initial proximity of these three icebergs, they followed very different trajectories across the South Atlantic until their eventual break-up and melting 1 year later. The largest, giant iceberg, B17a, spent extensive periods grounded near two different islands. The triplet's gradual melting is examined through the impact on the icebergs' dimensions, but also the meltwater's oceanic influence on the local salinity and primary productivity. It is found that there was generally a significant local surface and mixed-layer freshening of a few tenths of a practical salinity unit, up to several hundred kilometres away from the 10–20 km-sized icebergs. In contrast, the chlorophyll impact was highly temporally variable, although it tended to be larger in the summer. Break-up of these large icebergs did not occur until near the end of their life. We also show that modelling the trajectories of individual very large icebergs can be reasonable for up to 2 weeks if the characteristics of the iceberg and the local ocean and atmospheric forcing are well known.

Calving Event Led to Changes in Phytoplankton Bloom Phenology in the Mertz Polynya, Antarctica

AbstractPolynyas are subject to variability in winds and ocean circulation and are important sites of ecological productivity. In February 2010, the B09B iceberg collided with the Mertz Glacier Tongue (MGT), calving a 78 × 40‐km giant iceberg which modified the icescape and primary productivity of the Mertz polynya. In this study, we use satellite ocean color and sea ice concentration to investigate the variability, trends, and drivers of phytoplankton blooms in the Mertz polynya since 1997. During the bloom, over 21 years, we found (i) a later ice retreat time, (ii) an increase in sea ice concentration, (iii) a decrease in open‐water period, (iv) a later bloom start, and (v) a decrease in bloom duration. Our results suggest that major postcalving changes in the physical characteristics of the polynya, mainly its icescape, are the primary drivers of phytoplankton phenology. More specifically, the MGT calving event resulted in significant seasonal and regional changes, with higher eastern chl‐a and mean summer chl‐a postcalving. While satellite data are useful to study long‐term variability in these inhospitable areas, they only focus on the ocean surface and are obscured by ice and clouds. Additional subsurface parameters from seal tags, gliders and moorings in the southernmost polar regions would strengthen our comprehension of phytoplankton and physical changes in ocean dynamics that may have far‐reaching consequences, from global circulation to carbon export.

Changes in a Giant Iceberg Created from the Collapse of the Larsen C Ice Shelf, Antarctic Peninsula, Derived from Sentinel-1 and CryoSat-2 Data

The giant tabular iceberg A68 broke away from the Larsen C Ice Shelf, Antarctic Peninsula, in July 2017. The evolution of A68 would have been affected by both the Larsen C Ice Shelf, the surrounding sea ice, and the nearby shallow seafloor. In this study, we analyze the initial evolution of iceberg A68A—the largest originating from A68—in terms of changes in its area, drift speed, rotation, and freeboard using Sentinel-1 synthetic aperture radar (SAR) images and CryoSat-2 SAR/Interferometric Radar Altimeter observations. The area of iceberg A68A sharply decreased in mid-August 2017 and mid-May 2018 via large calving events. In September 2018, its surface area increased, possibly due to its longitudinal stretching by melting of surrounding sea ice. The decrease in the area of A68A was only 2% over 1.5 years. A68A was relatively stationary until mid-July 2018, while it was surrounded by the Larsen C Ice Shelf front and a high concentration of sea ice, and when its movement was interrupted by the shallow seabed. The iceberg passed through a bay-shaped region in front of the Larsen C Ice Shelf after July 2018, showing a nearly circular motion with higher speed and greater rotation. Drift was mainly inherited from its rotation, because it was still located near the Bawden Ice Rise and could not pass through by the shallow seabed. The freeboard of iceberg A68A decreased at an average rate of −0.80 ± 0.29 m/year during February–November 2018, which could have been due to basal melting by warm seawater in the Antarctic summer and increasing relative velocity of iceberg and ocean currents in the winter of that year. The freeboard of the iceberg measured using CryoSat-2 could represent the returned signal from the snow surface on the iceberg. Based on this, the average rate of thickness change was estimated at −12.89 ± 3.34 m/year during the study period considering an average rate of snow accumulation of 0.82 ± 0.06 m/year predicted by reanalysis data from the Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2). The results of this study reveal the initial evolution mechanism of iceberg A68A, which cannot yet drift freely due to the surrounding terrain and sea ice.

National Patient Safety Program in Brazil: Incidents Reported Between 2014 and 2017.

The aim of the study was to analyze the patient safety incidents reported to the Brazilian National Health Surveillance System from March 2014 to March 2017. A documentary study that used the records of the incidents published in the Reports of Adverse Events (AE) in Brazil. The following variables were selected: number of incidents by type, type of health service, hospital unit, and degree of harm. To find whether there was a significant difference across the Brazilian regions by notifications related to general incidents, AE, and deaths, the analysis of variance and the Tukey tests were used. A total of 109,082 incidents were reported, of which 75,088 were AE, with 649 deaths. In relation to the types of incidents reported, there was a higher frequency in the categories other (30.04%) and failures during health care (26.72%). A total of 93.90% of the incidents occurred in hospitals, with 54,950 cases registered in hospitalization units and 30,141 cases in intensive care units. Statistically significant differences across the Brazilian regions were observed in the number of incidents (P = 0.004), AE (P = 0.004), and deaths (P = 0.024). A significant underreporting of incidents was found in Brazil, demonstrating only the tip of a giant iceberg. More than half of the incidents were reported as AE and were registered in hospitals, reiterating the importance of establishing public health policies at national, state, and municipal levels, with adequate supervision of the health service regarding the implementation of the Patient Safety Nuclei and the preparation of new protocols based on the most prevalent incidents.

Icebergs, sea ice, blue carbon and Antarctic climate feedbacks.

Sea ice, including icebergs, has a complex relationship with the carbon held within animals (blue carbon) in the polar regions. Sea-ice losses around West Antarctica's continental shelf generate longer phytoplankton blooms but also make it a hotspot for coastal iceberg disturbance. This matters because in polar regions ice scour limits blue carbon storage ecosystem services, which work as a powerful negative feedback on climate change (less sea ice increases phytoplankton blooms, benthic growth, seabed carbon and sequestration). This resets benthic biota succession (maintaining regional biodiversity) and also fertilizes the ocean with nutrients, generating phytoplankton blooms, which cascade carbon capture into seabed storage and burial by benthos. Small icebergs scour coastal shallows, whereas giant icebergs ground deeper, offshore. Significant benthic communities establish where ice shelves have disintegrated (giant icebergs calving), and rapidly grow to accumulate blue carbon storage. When 5000 km2 giant icebergs calve, we estimate that they generate approximately 106 tonnes of immobilized zoobenthic carbon per year (t C yr−1). However, their collisions with the seabed crush and recycle vast benthic communities, costing an estimated 4 × 104 t C yr−1. We calculate that giant iceberg formation (ice shelf disintegration) has a net potential of approximately 106 t C yr−1 sequestration benefits as well as more widely known negative impacts.This article is part of the theme issue ‘The marine system of the West Antarctic Peninsula: status and strategy for progress in a region of rapid change’.

2017 in news: The science events that shaped the year.

A giant iceberg, a quantum-entanglement experiment and the death of a spacecraft are among the year’s top stories. A giant iceberg, a quantum-entanglement experiment and the death of a spacecraft are among the year’s top stories.

Chinese GF-1 and GF-3 satellites observed the giant iceberg calving off the Larsen C Ice Shelf

Chinese GF-1 and GF-3 satellites observed the giant iceberg calving off the Larsen C Ice Shelf

Impacts of the Larsen-C Ice Shelf calving event

A giant iceberg has calved off the Larsen-C Ice Shelf, the largest remaining ice shelf on the Antarctic Peninsula, reducing its total area by ~10%. Whilst calving events are a natural phenomenon and thus not necessarily indicative of changing environmental conditions, such events can impact ice-shelf stability.

The impact of the giant iceberg B09B on population size and breeding success of Adélie penguins in Commonwealth Bay, Antarctica

AbstractThe arrival of iceberg B09B in Commonwealth Bay, East Antarctica, and subsequent fast ice expansion has dramatically increased the distance Adélie penguins (Pygoscelis adeliae) breeding at Cape Denison must travel in search of food. This has provided a natural experiment to investigate the impact of iceberg stranding events and sea ice expansion along the East Antarctic coast. As part of the Australasian Antarctic Expedition 2013–14, the Adélie penguin colony at Cape Denison was censused to compare to historic counts. Whilst some 5520 pairs still bred at Cape Denison there has been an order of magnitude decline in Adélie numbers in the area in comparison to the first counts a century ago and, critically, recent estimates based on satellite images and a census in 1997. In contrast, an Adélie population on the eastern fringe of Commonwealth Bay just 8 km from the fast ice edge was thriving, indicating the arrival of B09B and fast ice expansion was probably responsible for the observed recent population decline. In conclusion, the Cape Denison population could be extirpated within 20 years unless B09B relocates or the now perennial fast ice within the bay breaks out. Our results have important implications for wider East Antarctic if the current increasing sea ice trend continues.

Freeboard and mass extraction of the disintegrated Mertz Ice Tongue with remote sensing and altimetry data

In February 2010, the Mertz Ice Tongue (MIT) collapsed and generated a giant iceberg. However, parameters about this iceberg have not been calculated and published in detail. In this study, the freeboard map of this iceberg was generated for the first time using a time-series ICESat/GLAS data. Methods for producing the freeboard map of this iceberg are suggested. Field data for ice velocity were used to relocate the footprints collected by different campaigns. Cross-validation was conducted with freeboards extracted from crossovers observed within 30days of each other. The precision of the freeboard extraction is approximately ±0.50m, when taking one standard deviation as the precision. The freeboard varied from 23m to 59m with the mean of 41m. With assumption of hydrostatic equilibrium (assuming a snow layer depth of 1m, a snow density of 360kg/m3, an ice density of 915kg/m3 and a sea water density of 1024kg/m3), the minimum, maximum and average ice thickness were calculated as 210m, 550m and 383m respectively. The total ice loss is approximately 8.96×1011tons over an area, 34km in width and 75km in length, or approximately 2560±5km2. These parameters extracted from remote sensing and altimetry data will provide additional information for studies of the evolution of iceberg, especially in iceberg tracking system.

Fateful (review)

Reviewed by: Fateful Kate Quealy-Gainer Gray, Claudia. Fateful. HarperTeen, 2011. [336p]. ISBN 978-0-06-200620-2 $17.99 Reviewed from galleys R Gr. 9–12. When she boards the RMS Titanic, maidservant Tess Davies has big plans for her arrival in America: after saving up for years, she will finally be able to resign from her post under the despotic Lady Regina (also aboard) and make a life for herself as a free woman. Unfortunately, her intentions do not take into account the giant iceberg that she and fellow passengers will soon become acquainted with, nor does she make accommodations for the fact that there appear to be werewolves onboard. [End Page 80] Yes, you read that correctly—werewolves on the Titanic, and yes, somehow it works. All the standard romance tropes, both paranormal and mundane, are here: girl (Tess) meets impossibly beautiful boy (Alec), boy turns out to be monster, girl and boy are inextricably drawn to each other and then viciously torn from each other by various machinations outside their control. Here, these obstacles happen to be, firstly, a sadistic Russian count (also a werewolf) who’s intent on bringing Alec under the control of the Brotherhood (the dominant mind-controlling pack) and, secondly, a rather large piece of frozen water. The plot is notably formulaic, but the chemistry between Alec and Tess is nearly flooding off the page, giving Kate and Leo a run for their money as Titanic’s most ardent couple. An admittedly kooky premise is nicely executed, as Gray delivers both an impressively detailed piece of historical fiction with nods to significant aspects of class and station as well as a swoonworthy romance sure to seduce lovers of all things were, vamp, and the like. Copyright © 2011 The Board of Trustees of the University of Illinois

Giant iceberg plow marks at more than 1 km water depth offshore West Greenland

During a recent (2006) cruise of RV ‘Dana’ high resolution side-scan sonar and sub-bottom profiling was carried out on selected shelf and slope transects offshore Disko Bugt, central West Greenland. Available commercial seismic data from the margin indicate here irregular seabed morphology with erosional features locally extending down to c. 1100 m water depth. The newly acquired side-scan sonar data reveal the presence of giant iceberg plow marks extending (sub)parallel to the slope between about 800 and 1085 m water depth. The height difference between bottom of the scours and rim crest is up to 40 m. The largest plow marks are about 750 m wide. To date no observed modern icebergs including those from Antarctica have drafts in excess of c. 500 m. Taking into account maximum glacial sea level lowering of c. 120 m, the paleo-iceberg keel depth was at least 950 m. Due to the presence of the relatively shallow (< 700 m) sill of Davis Strait to the south, calving of these paleo-icebergs is thought to have occurred from an ice margin in the Baffin Bay region (Jakobshavn Isbræ paleo-ice stream?). The depth of occurrence (> 1000 m) and dimensions of the plow marks are concluded to be exceptional, and comparable to glacial scouring features reported from the Arctic Ocean.

Giant iceberg grinds to a halt

Giant iceberg grinds to a halt

'Karta nashei Rodiny': ideologema mezhdu slovom i telom by Gasan Guseinov (review)

586 SEER, 79, 3, 200 I theirrange and content can be gained from the English-languagesummaryat the end. School ofHistory A. F. UPTON TheUniversity ofStAndrews Guseinov, Gasan. 'Karta nashei Rodiny'ideologema mezhdu slovom i telom. Institute for Russian and East European Studies, Helsinki, 2000. 266 pp. Illustrations . Notes. FIM 8o.oo. IN what is almost certainly the first book of its kind, Gasan Guseinov has collected an immense amount of verbal and pictorial material to illustrate Russianreactionsto the perceived differencesin the shape and natureof their country since Gorbachev started the reform process. Comprehensively annotated from mainly Russian and German sources, and written in a far from populist style, this study is not only interesting but even entertaining, thanksto the profusionof quotationsand pictures.The latter, I43 in number, mostly consist of real or imaginarymaps, and of political cartoons. They are printedafterthe writtentext, and takeup more than halfthe number of pages in the book;with few exceptions, they arereferredto in the text. Although this means a lot of page-turning, it is hard to see, with such a volume of illustrations,how it could have been done otherwise. Certainly,the selection of illustrativematerial,both verbaland pictorial,is remarkablefor its breadth and itsaptness. The first of the sixteen sections is devoted to a key neologism used throughout, namely Uwe Porksen's 'visiotype', a word cognate to 'idol', 'emblem' or 'symbol' which is particularly useful for discussion of the Fatherlandas described by the Russian mass media after I99I. One of the most important visiotypes for Russians remains the map of the USSR, and Guseinov'ssecond section is entitled 'The map and frontieron the matrixof a cognitive map', continuing with two sections on the iron curtain, and in particularthe frontier'sdottedline and the frontierpost asambiguoussymbols for the ex-Soviet mentality (this provides a particularlyfertile field for the cartoonists). The topic of the globe and Russia's place on it is followed by 'One sixth: geopolitical space, or global organism', a territory that was, of course, considerablyeroded by the release of the satellitecountriesand many Soviet republicsin what became known in the Russianpressas the 'paradeof the sovereignties' (p. I6). Another powerful visiotype, particularly in poetry, is of Russia as a body and this is the subject of the seventh section, followed by a discussion of the concepts of 'betrayal' and 'dismemberment' where Guseinov notes that a characteristic feature of the visiotype is that 'it immediately suggests that a natural tendency or chain of events is a plot consciously directed at the relevant country' (p. 43). Next the author considers the concept of authenticity and the visiotype, and 'The visiotype and war in discourse', in the course of the latter, highlighting an absurd debate in the press on the use of the word 'front' in non-military contexts (pp. 54-56). The section entitled 'Organic metaphorics and historical masquerade' provides a rare example of Guseinov REVIEWS 587 stretching a point, when he suggests the presence of personification in the phrase 'cold schools' (p. 62). This is followed by 'The collapse of the USSR and the discourse of emptiness' after which comes 'The filling in of the emptiness',illustratedby a particularlysavagequotationfromthepoet Aleksei Parshchikov:'Whetheryou are territoryor a girl does not matter, in [a world where] the word has gone wild' (p. 80). Fourexamplesaregiven of the trapsto which discourseisprone when using visiotypes: V. Tsymburskii's Russia as an island; D. Galkovskii's broken compass; A. Dugin's mysteries of Eurasia; and A. T. Fomenko's new chronology (breathtakingly,deriving Batyj from bat'ko[father] and Mamai from mama[p. 97]). The last two sections are devoted to the visiotype of dispersal, where Guseinov leaves behind his review of caricature and 'philosophical occultism' in favour of 'pragmatic cartographic publicistics' (p. 99), adducinga flood of conspiracytheoriesto explain Russia'sisolationas a giant iceberg, with, moreover, asiatic characteristics.The last section is, indeed, entitled 'Russia or Northern Asia', in which the author incorporates in its entiretyan annotatedballadby EvgeniiRepin (pp. II8- I9). This fascinatingstudy of national paranoia is slightlymarred by technical glitches, such as occasional missing words, lines and references (pp. 8, i o6, I 22), transposed letters (pp. 76, I90) and misplaced punctuation (pp. 5I, 52). All these may be forgiven, however, in view...

Rural Property and Economy in Post-Communist Albania by Harold s&gt; Lemel (review)

REVIEWS 587 stretching a point, when he suggests the presence of personification in the phrase 'cold schools' (p. 62). This is followed by 'The collapse of the USSR and the discourse of emptiness' after which comes 'The filling in of the emptiness',illustratedby a particularlysavagequotationfromthepoet Aleksei Parshchikov:'Whetheryou are territoryor a girl does not matter, in [a world where] the word has gone wild' (p. 80). Fourexamplesaregiven of the trapsto which discourseisprone when using visiotypes: V. Tsymburskii's Russia as an island; D. Galkovskii's broken compass; A. Dugin's mysteries of Eurasia; and A. T. Fomenko's new chronology (breathtakingly,deriving Batyj from bat'ko[father] and Mamai from mama[p. 97]). The last two sections are devoted to the visiotype of dispersal, where Guseinov leaves behind his review of caricature and 'philosophical occultism' in favour of 'pragmatic cartographic publicistics' (p. 99), adducinga flood of conspiracytheoriesto explain Russia'sisolationas a giant iceberg, with, moreover, asiatic characteristics.The last section is, indeed, entitled 'Russia or Northern Asia', in which the author incorporates in its entiretyan annotatedballadby EvgeniiRepin (pp. II8- I9). This fascinatingstudy of national paranoia is slightlymarred by technical glitches, such as occasional missing words, lines and references (pp. 8, i o6, I 22), transposed letters (pp. 76, I90) and misplaced punctuation (pp. 5I, 52). All these may be forgiven, however, in view of two more slips: 'N[inel?] Lenin' (P. 29) and 'I. V. Sralin' (p. 38). In view of Guseinov's subject they are hardly likely to be taken as accidental by many of those quoted in this study. Original and richly documented, this monograph presents a vivid and depressing picture of a country trying to come to terms with a major change of status. Gasan Guseinov manages far better with his analysis than did John Foster Dulles in the case of Britain, insofar as that he is entertaining as well as enlightening. This thoroughly researched and richly illustrated book deserves a wide readership amongst modern historians and, indeed, all who have been watching with a mixture of pity and horror the ongoing travails of post-Soviet Russia. SchoolofSlavonicandEast EuropeanStudies ARNOLD MCMILLIN University College London Lemel, Harold (ed.). RuralProperty and Economy in Post-Communist Albania. Berghahn, New Yorkand Oxford, 2000. xxiii + I6o pp. Notes. Tables. Figures.Index. ?3o.OO. NATIONWIDE rioting in 199I-92 and in 1997 contributed to the worst postCommunist production decline in eastern Europe, outside war-torn former Yugoslavia.The disorderof I99l-92 was mainlyrural,comprisingthe seizure of land and the ravaging of state assets: the stripping of public buildings, schools and health centres was an insensateprotest againstforty-fiveyears of bondage to the state, but the theft of fencing and the ripping up of railway sleepers and signal wire were motivated by the need quickly to demarcate villagers' land as Albania's particularly repressive collective farming was abandoned.The insurgencyof 1997 wasurban,sparkedby investorsfrustrated 588 SEER, 79, 3, 200 I at lack of redress against the politically well-connected fraudsters of the pyramid schemes. It was furtherfired by protest against the rigged general election of the previous year which had upheld an increasinglyauthoritarian president.Army arsenalswere looted and by mid-2ooo halfa millionweapons were stillprivatelysecretedwithin the countryor in Kosova. It was in the years I 993-96, between these two 'times of troubles',that Dr Harold Lemel, a land tenure consultantwho had advisedgovernmentsin the Middle East, Africa, East Asia and the Caribbean, headed village surveys underthe auspicesof the MinistryofAgricultureand the LandTenure Center of the University of Wisconsin at Madison with fundingfrom the WorldBank and USAID. The Wisconsin Center was administeringin Tirana a national Immovable Property Registration System (IPRS) and provided three of the contributorsto this book, Peter Bloch and Susana Lastarria-Cornhielon its staffand Rachel Wheeler, then a doctoral student. The fourth contributoris the Albanian Registrar of Lands, Albert Dubali. Lemel writes four of the chapters(methodology;involvement in farming;tenure security;and land use and investment)and one eachjointly with Wheeler (creditaccess)and Dubali (landfragmentation);Blochwritesone (ruralpropertymarkets);andLastarriaCornhiel and Wheeler together explore implications for gender roles (family and propertyrights). The need for a LandRegistryand an IPRS arosefromthe obliterationof possessionalboundariesand the invalidationof the familytapi(landcertificate) by the collectivization campaign of 1957-60. Lamel's surveyposed...

Modeling giant-iceberg drift under the influence of sea ice in the Weddell Sea, Antarctica

AbstractThe drift trajectory of giant iceberg C-7 traversing the Weddell Sea, Antarctica, for &gt; 2 years was successfully simulated. Application of the “classical” driving forces like wind and ocean currents resulted in a significant discrepancy between modeled and observed iceberg velocities in the western Weddell Sea. The most realistic drift pattern in space and time was achieved by adding a sea-ice force which represents the ability of a dense sea-ice cover (≥90%) to lock in icebergs and collect the momentum of the wind over an area much larger than the area of the iceberg proper. This process was parameterized using a sea-ice strength P which depends on sea-ice concentration and thickness, both having highest values in winter and in the western Weddell Sea which is covered with multi-year sea ice. As a consequence of the sensitivity to sea ice, the timing of the iceberg drift becomes important, revealing the region off Brunt Ice Shelf (eastern Weddell Sea) as a location where bergs either continue westward with the coastal current or follow a southern branch onto the shallow continental shelf.

Giant iceberg breaks off

Giant iceberg breaks off

The drift of a giant iceberg in the Weddell Sea

Abstract The authors provide details of the calving of a giant iceberg, measuring some 75 X 75 km, from the front of the Larsen Ice Shelf in the Weddell Sea in 1986. They plotted its drift for some 5 months using satellite imagery. They suggest that such giant icebergs might be used as research platforms for studying a wide range of scientific areas.