During the summer months,Adélie penguins represent the dominant biomass of terrestrial Antarctica.Literally millions of individuals nest in ice-free areas around the coast of the continent.Hence,these modern popu...During the summer months,Adélie penguins represent the dominant biomass of terrestrial Antarctica.Literally millions of individuals nest in ice-free areas around the coast of the continent.Hence,these modern populations of Adélie penguins have often been championed as an ideal biological indicator of ecological and environmental changes that we currently face.In addition,Adélie penguins show an extraordinary record of sub-fossil remains,dating back to the late Pleistocene.At this time,temperatures were much lower than now.Hence,this species offers unique long-term information,at both the genomic and ecological levels,about how a species has responded to climate change over more than 40000 years.展开更多
La V. Narcanello è caratterizzata, nella sua parte sommitale, dalla Vedretta di Pisganae dall’apparato morenico della sua porzione occidentale, presso il quale sono maggiormente conservatele evidenze delle varia...La V. Narcanello è caratterizzata, nella sua parte sommitale, dalla Vedretta di Pisganae dall’apparato morenico della sua porzione occidentale, presso il quale sono maggiormente conservatele evidenze delle variazioni oloceniche. Sulla base di osservazioni morfologiche, stratigrafiche, tessiturali,dello stato di aherazione dei depositi, sull’osservazione del grado di lichenizzazione, dello sviluppo deisuoli e di date <sup>14</sup>C, sono state differenziate le varie morene. Un’avanzata olocenica del ghiacciaio diPisgana occidentale, attribuibile al Neoglaciale, è stata individuata sulla base di due date <sup>14</sup>C che inqua-drano l’evento in un periodo compreso tra 3350/3086 e 2706/2207 anni dal presente. Dall’inizio delXX sec. ad oggi, il ghiacciaio di Pisgana occidentale ha santo un generale ritiro di circa 1000 m, conbrevi e limitati periodi di riavanzata, il più cospicuo dei quali si coloca trail 1939 ed il 1941 （circa40 m）. A questa nota è allegata una carta geomorfologica dell’alta V. Narcanello.Vedretta of Pisgana （Adamello Group）. Geomorphology and Holocene front variations.The Vedretta of Pisgana is located in the upper Narcanello Valley and it terminates with three distinctfronts. The western tongue is the best developed and it deposited several moraines which document Holo-cene front variations. Late Glacial and Holocene moraines of the Narcanello Valley have been differentia-ted on the basis of morphological, stratigraphical, textural observations, （14）<sup>C</sup> dates and of the weathe-ring degree of the glacial deposits as well as lichenization and soil development. From the left side ofNarcanello Valley comes the oldest <sup>14</sup>C date so far obtained in the Adamello Group. A buried soil foundat 2545 m a.s.l, between two lateral moraines, Late Glacial and Holocene respectively, yielded an ageof 6600 ± 100 <sup>14</sup>C yr BP （GX-14711）. In the same area two dates bracket a Neoglacial advance ofthe western portion of the Vedretta of Pisgana. The maximum- limiting age is 3015 ±75 <sup>14</sup>C yr BP（GX-14712）, while the minimum-limiting age for the Pisgana glacier advance is 2345 ±125 <sup>14</sup>C yrBP （GX-14710）. The western portion of the Vedretta of Pisgana retreated about 1000 m since the firstyears of the XX Century. Three small advances also occurred, the widest between 1939 and 1941 （about40 m）. A geomorphological map of the upper Narcanello Valley completes this note.展开更多
文摘During the summer months,Adélie penguins represent the dominant biomass of terrestrial Antarctica.Literally millions of individuals nest in ice-free areas around the coast of the continent.Hence,these modern populations of Adélie penguins have often been championed as an ideal biological indicator of ecological and environmental changes that we currently face.In addition,Adélie penguins show an extraordinary record of sub-fossil remains,dating back to the late Pleistocene.At this time,temperatures were much lower than now.Hence,this species offers unique long-term information,at both the genomic and ecological levels,about how a species has responded to climate change over more than 40000 years.
文摘La V. Narcanello è caratterizzata, nella sua parte sommitale, dalla Vedretta di Pisganae dall’apparato morenico della sua porzione occidentale, presso il quale sono maggiormente conservatele evidenze delle variazioni oloceniche. Sulla base di osservazioni morfologiche, stratigrafiche, tessiturali,dello stato di aherazione dei depositi, sull’osservazione del grado di lichenizzazione, dello sviluppo deisuoli e di date <sup>14</sup>C, sono state differenziate le varie morene. Un’avanzata olocenica del ghiacciaio diPisgana occidentale, attribuibile al Neoglaciale, è stata individuata sulla base di due date <sup>14</sup>C che inqua-drano l’evento in un periodo compreso tra 3350/3086 e 2706/2207 anni dal presente. Dall’inizio delXX sec. ad oggi, il ghiacciaio di Pisgana occidentale ha santo un generale ritiro di circa 1000 m, conbrevi e limitati periodi di riavanzata, il più cospicuo dei quali si coloca trail 1939 ed il 1941 （circa40 m）. A questa nota è allegata una carta geomorfologica dell’alta V. Narcanello.Vedretta of Pisgana （Adamello Group）. Geomorphology and Holocene front variations.The Vedretta of Pisgana is located in the upper Narcanello Valley and it terminates with three distinctfronts. The western tongue is the best developed and it deposited several moraines which document Holo-cene front variations. Late Glacial and Holocene moraines of the Narcanello Valley have been differentia-ted on the basis of morphological, stratigraphical, textural observations, （14）<sup>C</sup> dates and of the weathe-ring degree of the glacial deposits as well as lichenization and soil development. From the left side ofNarcanello Valley comes the oldest <sup>14</sup>C date so far obtained in the Adamello Group. A buried soil foundat 2545 m a.s.l, between two lateral moraines, Late Glacial and Holocene respectively, yielded an ageof 6600 ± 100 <sup>14</sup>C yr BP （GX-14711）. In the same area two dates bracket a Neoglacial advance ofthe western portion of the Vedretta of Pisgana. The maximum- limiting age is 3015 ±75 <sup>14</sup>C yr BP（GX-14712）, while the minimum-limiting age for the Pisgana glacier advance is 2345 ±125 <sup>14</sup>C yrBP （GX-14710）. The western portion of the Vedretta of Pisgana retreated about 1000 m since the firstyears of the XX Century. Three small advances also occurred, the widest between 1939 and 1941 （about40 m）. A geomorphological map of the upper Narcanello Valley completes this note.
