Age and taphonomy of abandoned penguin rookeries in the Antarctic Peninsula region

Polar Record ◽  
1995 ◽  
Vol 31 (179) ◽  
pp. 409-418 ◽  
Author(s):  
Steven D. Emslie
Keyword(s):  
Antarctic Peninsula ◽  
Little Ice Age ◽  
Distribution Patterns ◽  
Ice Age ◽  
Pygoscelis Adeliae ◽  
Radiocarbon Dates ◽  
Breeding Sites ◽  
Modern Distribution ◽  
The Antarctic ◽  
Systematic Collection

ABSTRACTInvestigations on the age and taphonomy of modern and abandoned penguin rookeries were completed in the Antarctic Peninsula region, 1992–1994. Systematic collection and identification of bones from modern rookeries of Adélie (Pygoscelis adeliae), chinstrap (P. antarctica), and gentoo (P. papua) penguins indicate a bias in element preservation for humeri, furcula, femora, and tibiotarsi. More than 73% of the individuals represented by these elements are juveniles. Bones from abandoned rookeries show similar patterns that can help identify old breeding sites and the species that occupied them. Radiocarbon dates completed on 13 chinstrap and Adélie penguin bones, feathers, and eggshell fragments from five abandoned rookeries suggest that occupation of these sites occurred only during warm intervals of the Little Ice Age (AD 1500–1850). These data also provide information on the paleoecology and paleobiogeography of penguins in the Antarctic Peninsula region, which help explain modern distribution patterns and demography.

Abandoned penguin colonies and environmental change in the Palmer Station area, Anvers Island, Antarctic Peninsula

1998 ◽  
Vol 10 (3) ◽  
pp. 257-268 ◽  
Author(s):  
Steven D. Emslie ◽  
William Fraser ◽  
Raymond C. Smith ◽  
William Walker
Keyword(s):  
Antarctic Peninsula ◽  
Little Ice Age ◽  
Ice Age ◽  
Before Present ◽  
Pygoscelis Adeliae ◽  
Regional Warming ◽  
The Past ◽  
Palmer Station ◽  
History Of ◽  
Adélie Penguins

Six abandoned colonies of Adélie penguin (Pygoscelis adeliae) were excavated near Palmer Station, Anvers Island, Antarctic Peninsula, to investigate the occupation history of this species. Sediments from each site yielded abundant fish bones and otoliths and squid beaks that represent prey remains deposited by penguins during the nesting period. Radiocarbon analyses indicate that colony occupation began prior to the Little Ice Age (LIA; 1500–1850 AD), with the oldest site dating to 644 yrs before present (BP; average reservoir-corrected date with Is range, 603–679 yr BP). Food remains indicate that the non-euphausiid prey of penguins consisted primarily of a mesopelagic squid (Psychroteuthis glacialis) and two species of fish (Pleuragramma antarcticun and Electrona antarctica). The relative abundance of the first two prey taxa varied significantly among six sites (X2>34.6; df = 10; P <0.001) with colonies dating prior to the LIA having greater representation of squid, and less of silverfish, than those occupied during the LIA. Data from control excavations at three modern colonies indicate a diet similar to that of the pre-LIA sites. These results suggest that Adélie penguins may have changed their diet in response to warming and cooling cycles in the past. In addition, only Adélie penguins are known to have nested in the Palmer Station area prior to the l950s; gentoo (Pygoscelis papua) and chinstrap (P. antarctica) penguins now breeding in this region have expanded their ranges southward in the Peninsula within the past 50 yrs, in correlation with pronounced regional warming.

scholarly journals Evidence for a “Little Ice Age” glacial advance within the Antarctic Peninsula – Examples from glacially-overrun raised beaches

2021 ◽  
Vol 271 ◽  
pp. 107195
Author(s):  
Alexander R. Simms ◽  
Michael J. Bentley ◽  
Lauren M. Simkins ◽  
Julie Zurbuchen ◽  
Laura C. Reynolds ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Little Ice Age ◽  
Ice Age ◽  
The Antarctic ◽  
Raised Beaches ◽  
Glacial Advance

A 1000-year record of Adélie penguin diets in the southern Ross Sea

2002 ◽  
Vol 14 (4) ◽  
pp. 327-332 ◽  
Author(s):  
MICHAEL POLITO ◽  
STEVEN D. EMSLIE ◽  
WILLIAM WALKER
Keyword(s):  
Ross Sea ◽  
Prey Selection ◽  
Ice Age ◽  
Adélie Penguin ◽  
Pleuragramma Antarcticum ◽  
Adelie Penguin ◽  
Radiocarbon Dates ◽  
Antarctic Silverfish ◽  
The Antarctic

Non-krill prey remains were recovered from ornithogenic sediments at three active Adélie penguin colonies on Ross Island, to assess long-term dietary trends in this species. Radiocarbon dates place the age of these deposits from a maximum of 947 years ago to the present. We identified 12 taxa of fish and two of squid with the Antarctic silverfish (Pleuragramma antarcticum) as the most abundant prey species represented at all sites. In addition, silverfish have decreased in importance in Adélie penguin diet over the past 600 years, perhaps in response to climate change since the onset of the Little Ice Age, though it remains much more abundant in current penguin diet in the Ross Sea than in the Antarctic Peninsula. Other prey taxa reflect the diversity of prey selection by Adélie penguins in Antarctica.

Pattern and Forcing of Northern Hemisphere Glacier Variations During the Last Millennium

1986 ◽  
Vol 26 (1) ◽  
pp. 27-48 ◽  
Author(s):  
Stephen C. Porter
Keyword(s):  
Northern Hemisphere ◽  
Little Ice Age ◽  
Ice Core ◽  
Volcanic Eruptions ◽  
Ice Age ◽  
Phase Lag ◽  
Mountain Glacier ◽  
Radiocarbon Dates ◽  
Glacier Fluctuations ◽  
Decadal Scale

Time series depicting mountain glacier fluctuations in the Alps display generally similar patterns over the last two centuries, as do chronologies of glacier variations for the same interval from elsewhere in the Northern Hemisphere. Episodes of glacier advance consistently are associated with intervals of high average volcanic aerosol production, as inferred from acidity variations in a Greenland ice core. Advances occur whenever acidity levels rise sharply from background values to reach concentrations ≥1.2 μequiv H+/kg above background. A phase lag of about 10–15 yr, equivalent to reported response lags of Alpine glacier termini, separates the beginning of acidity increases from the beginning of subsequent ice advances. A similar relationship, but based on limited and less-reliable historical data and on lichenometric ages, is found for the preceding 2 centuries. Calibrated radiocarbon dates related to advances of non-calving and non-surging glaciers during the earlier part of the Little Ice Age display a comparable consistent pattern. An interval of reduced acidity values between about 1090 and 1230 A.D. correlates with a time of inferred glacier contraction during the Medieval Optimum. The observed close relation between Noothern Hemisphere glacier fluctuations and variations in Greenland ice-core acidity suggests that sulfur-rich aerosols generated by volcanic eruptions are a primary forcing mechanism of glacier fluctuations, and therefore of climate, on a decadal scale. The amount of surface cooling attributable to individual large eruptions or to episodes of eruptions is simlar to the probable average temperature reduction during culminations of Little Ice Age alacier advances (ca. 0.5°–1.2°C), as inferred from depression of equilibrium-line altitudes.

Late Glacial and Late Holocene Moraines in the Cerros Cuchpanga, Central Peru

1984 ◽  
Vol 21 (3) ◽  
pp. 275-285 ◽  
Author(s):  
H.E. Wright
Keyword(s):  
Little Ice Age ◽  
Late Holocene ◽  
Late Glacial ◽  
Ice Age ◽  
Recent Past ◽  
Valley Bottom ◽  
Radiocarbon Dates ◽  
Western Cordillera ◽  
Limestone Bedrock ◽  
Ice Field

Small ice fields on the western cordillera northeast of Lima were expanded to three times their present size in the recent past, and the regional snow line was probably about 100 m lower than it is today. Outwash from the expanded glaciers formed deltas of silt in valley-bottom lakes. When the ice lobes retreated, the reduced outwash was trapped behind recessional moraines, and the clear meltwater infiltrated into the limestone bedrock and emerged at the heads of the deltas in spring pools. The delta surfaces then became covered with peat, and radiocarbon dates for the base of the peat (1100 ± 70 and 430 ± 70 yr B.P. for two different deltas) indicate that the maximum ice advance was older than those dates and, thus, older than the Little Ice Age of many north-temperate regions. Much older moraines date from expansion of the same local summit glaciers to even lower levels in the main valleys, which had previously been inundated by the cordilleran ice field. The cordilleran deglaciation and this expansion of local glaciers probably occurred between 12,000 and 10,000 yr ago, on the basis of slightly contradictory radiocarbon dates.

scholarly journals Glacier Fluctuations in George VI Sound Area, West Antarctica (Abstract only)

1982 ◽  
Vol 3 ◽  
pp. 345 ◽  
Author(s):  
C.M. Clapperton ◽  
D.E. Sugden
Keyword(s):  
Antarctic Peninsula ◽  
Ice Age ◽  
List Type ◽  
West Antarctica ◽  
Ice Shelf ◽  
Scotia Sea ◽  
Field Evidence ◽  
Glacial Chronology ◽  
History Of ◽  
The Antarctic

George VI Sound lies between Alexander Island and the Antarctic Peninsula and is over 20 km wide and 500 km long. At present an ice shelf fills the sound and is nourished largely by ice from the Antarctic Peninsula which flows across the sound to ground against the coast of Alexander Island. Ice-free areas, comprising small nunataks and larger massifs, fringe both sides of the sound and contain evidence of the former glacial history of the area. This paper describes the field evidence in detail and uses geomorphological and sedimentary analyses to put forward a relative glacial chronology, constrained by two absolute dates. The chronology distinguishes: (1) a maximum state during which all ice-free areas were submerged by ice flowing into George VI Sound from both the Antarctic Peninsula and Alexander Island and thence along the sound as an ice stream. This occurred in the late Wisconsin and followed an interstadial or interglacial when George VI Sound was free of an ice shelf. (2) a valley-based stadial during overall deglaciation represented by pronounced marginal moraines on Alexander Island. (3) deglaciation to a stage where there was less landbased ice on Alexander Island than today. At this stage isostatic recovery was incomplete, relative sealevel was higher, and George VI Ice Shelf penetrated further into embayments on Alexander Island than at present. (4) probable disappearance of George VI Ice Shelf by 6.5 14C ka BP. (5) neoglacial readvance of local glaciers on Alexander Island to form three closely spaced terminal moraines and the growth of a new George VI Ice Shelf which was again more extensive than at present. (6) subsequent oscillations of both smaller Alexander Island glaciers and George VI Ice Shelf probably during the Little Ice Age. These fluctuations are similar to those in other sub-Antarctic Islands in the Scotia Sea and also in southern Chile.

Late Holocene advance of the Müller Ice Shelf, Antarctic Peninsula: sedimentological, geochemical and palaeontological evidence

1995 ◽  
Vol 7 (2) ◽  
pp. 159-170 ◽  
Author(s):  
Eugene W. Domack ◽  
Scott E. Ishman ◽  
Andrew B. Stein ◽  
Charles E. McClennen ◽  
A.J. Timothy Jull
Keyword(s):  
Antarctic Peninsula ◽  
Deep Water ◽  
Sediment Cores ◽  
Austral Summer ◽  
Ice Age ◽  
Geochemical Data ◽  
Organic Carbon Content ◽  
Ice Shelf ◽  
Circumpolar Deep Water ◽  
The Antarctic

Marine sediment cores were obtained from in front of the Müller Ice Shelf in Lallemand Fjord, Antarctic Peninsula in the austral summer of 1990–91. Sedimentological and geochemical data from these cores document a warm period that preceded the advance of the Müller Ice Shelf into Lallemand Fjord. The advance of the ice shelf is inferred from a reduction in the total organic carbon content and an increase in well-sorted, aeolian, sand in cores proximal to the present calving line. This sedimentological change is paralleled by a change in the foraminiferal assemblages within the cores. Advance of the ice shelf is indicated by a shift from assemblages dominated by calcareous benthic and planktonic forms to those dominated by agglutinated forms. A 14C chronology for the cores indicates that the advance of the Müller Ice Shelf took place c. 400 years ago, coincident with glacier advances in other high southern latitude sites during the onset of the Little Ice Age. Ice core evidence, however, documents this period as one of warmer temperatures for the Antarctic Peninsula. We suggest that the ice shelf advance was linked to the exclusion of circumpolar deep water from the fjord. This contributed to increased mass balance of the ice shelf system by preventing the rapid undermelt that is today associated with warm circumpolar deep water within the fjord. We also document the recent retreat of the calving line of the Müller Ice Shelf that is apparently in response to a recent (four decade long) warming trend along the western side of the Antarctic Peninsula.

scholarly journals Palynological evidence from a sub-alpine marsh of enhanced Little Ice Age snowpack in the Marrakech High Atlas, North Africa

2021 ◽  
Author(s):  
Benjamin A. Bell ◽  
William J. Fletcher ◽  
Philip D. Hughes ◽  
Henk L. Cornelissen ◽  
David Fink ◽  
...  
Keyword(s):  
20Th Century ◽  
Little Ice Age ◽  
Management Practices ◽  
Accumulation Point ◽  
Ice Age ◽  
Pollen Record ◽  
Climatic Fluctuations ◽  
Radiocarbon Dates ◽  
High Atlas ◽  
Grazing Impacts

AbstractThe grazing lands of the High Atlas are vulnerable to climate change and the decline of traditional management practices. However, prior to the mid-20th century, there is little information to examine historical environmental change and resilience to past climate variability. Here, we present a new pollen, non-pollen palynomorph (NPP) and microcharcoal record from a sub-alpine marsh (pozzine) at Oukaïmeden, located in the Marrakech High Atlas, Morocco. The record reveals a history of grazing impacts with diverse non-arboreal pollen assemblages dominant throughout the record as well as recurrent shifts between wetter and drier conditions. A large suite of radiocarbon dates (n = 22) constrains the deposit to the last ~ 1,000 years although multiple reversed ages preclude development of a robust age-depth model for all intervals. Between relatively dry conditions during the Medieval period and in the 20th century, intervening wet conditions are observed, which we interpret as a locally enhanced snowpack during the Little Ice Age. Hydrological fluctuations evidenced by wetland pollen and NPPs are possibly associated with centennial-scale precipitation variability evidenced in regional speleothem records. The pollen record reveals an herbaceous grassland flora resilient against climatic fluctuations through the last millennium, possibly supported by sustainable collective management practices (agdal), with grazing indicators suggesting a flourishing pastoral economy. However, during the 20th century, floristic changes and increases in charcoal accumulation point to a decline in management practices, diversification of land-use (including afforestation) and intensification of human activity.

scholarly journals The evolution of the Patagonian Ice Sheet from 35 ka to the Present Day (PATICE)

2020 ◽  
Author(s):  
Bethan Davies ◽  
Keyword(s):  
Little Ice Age ◽  
Ice Sheet ◽  
Ice Age ◽  
Shelf Edge ◽  
Ice Streams ◽  
Glacial Geomorphology ◽  
Outlet Glacier ◽  
Southern South America ◽  
The Pacific ◽  
The Antarctic

&lt;p&gt;We present PATICE, a GIS database of Patagonian glacial geomorphology and recalibrated chronostratigraphic data. PATICE includes 58,823 landforms and 1,669 ages, and extends from 38&amp;#176;S to 55&amp;#176;S in southern South America. We use these data to generate new empirical reconstructions of the Patagonian Ice Sheet (PIS) and subsequent ice masses and ice-dammed palaeolakes at 35 ka, 30 ka, 25 ka, 20 ka, 15 ka, 13 ka (synchronous with the Antarctic Cold Reversal), 10 ka, 5 ka, 0.2 ka (synchronous with the &amp;#8220;Little Ice Age&amp;#8221;) and 2011 AD. At 35 ka, the PIS covered of 492.6 x10&lt;sup&gt;3 &lt;/sup&gt;km&lt;sup&gt;2&lt;/sup&gt;, had a sea level equivalent of ~1,496 mm, was 350 km wide and 2090 km long, and was grounded on the Pacific continental shelf edge. Outlet glacier lobes remained topographically confined and the largest generated the suites of subglacial streamlined bedforms characteristic of ice streams. The PIS reached its maximum extent at 33 &amp;#8211; 28 ka from 38&amp;#176;S to 48&amp;#176;S, and earlier, around 47 ka from 48&amp;#176;S southwards. Net retreat from maximum positions began by 25 ka, with ice-marginal stabilisation at 21 &amp;#8211; 18 ka, followed by rapid deglaciation. By 15 ka, the PIS had separated into disparate ice masses, draining into large ice-dammed lakes along the eastern margin, which strongly influenced rates of recession. Glacial readvances or stabilisations occurred at 14 &amp;#8211; 13 ka, 11 ka, 5 &amp;#8211; 6 ka, 1 &amp;#8211; 2 ka, and 0.2 ka. We suggest that 20&lt;sup&gt;th&lt;/sup&gt; century glacial recession is occurring faster than at any time documented during the Holocene.&amp;#160;&lt;/p&gt;

scholarly journals Dynamics of Numbers and Occurrence of Colonial Species of Birds in the Area of Ukrainian Antarctic Station Akademik Vernadsky

2019 ◽  
Vol 53 (6) ◽  
pp. 491-500
Author(s):  
V. M. Smagol ◽  
D. V. Pilipenko ◽  
A. O. Dzhulai
Keyword(s):  
Antarctic Peninsula ◽  
Water Area ◽  
Gentoo Penguin ◽  
Chinstrap Penguin ◽  
Pygoscelis Adeliae ◽  
The North ◽  
Pygoscelis Antarctica ◽  
Time Gap ◽  
The Antarctic ◽  
Green Island

Abstract The research covers water area, island archipelagos and coastal line of the Antarctic Peninsula from 65°31ʹ S, 64°25ʹ W in the South to 65°03ʹ S, 63°53ʹ W in the North. There was time gap of 7 years between the researches (2011 and 2018), which allows to define tendencies in development of individual colonies and to make conclusion about success of existence of a given species. The work itself was carried out during the first half of January, that is in the time when the stage of brooding ends and the period of hatching starts. As of 2011, 12 nesting points of gentoo penguin (Pygoscelis papua) with total number of 8,342 pairs were found in the region under investigation. Till 2018, quantity of the colony grew to 14, with total number of 14,105 pairs. For seven years, quantity of nesting points of aelie penguin (Pygoscelis adeliae) almost did not change (4 colonies). Instead, total number of the species decreased somewhat: from 3559 pairsin 2011 to 3295 onesin 2018. Number of chinstrap penguin (Pygoscelis antarctica) in united stable locality for nesting also decreased from 26 pairsin 2011 to19 onesin 2018. Booth Island (65°04ʹ S, 64°02ʹ W) for chinstrap penguins and Green Island (65°19ʹ S, 64°09ʹ W) for gentoo penguins are the southern most points of nesting range of the species. Also, 7 colonies of antarctic shag (Phalacrocorax bransfieldensis) were revealed in the region under investigation. For seven years from 2011 to 2018 total number of the species in the region under investigation grew from 190 pairs to 299, and in most cases the antarctics shag forms settlements jointly with penguins.

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