Late-Holocene record of environmental changes in the Ross Sea: from seasonal to centennial time scales.
We present data from a laminated sediment core collected in the Edisto inlet (Ross Sea, Antarctica). The expanded record (14.6 m long) covers the last ca. 2800 years and it is dominated by dark- and light-brown diatom oozes. We used a suite of proxies which include diatom assemblages, bulk OC and TN...
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ftunivpisairis:oai:arpi.unipi.it:11568/1035824 2024-04-14T08:03:41+00:00 Late-Holocene record of environmental changes in the Ross Sea: from seasonal to centennial time scales. Tesi T. Langone L. Gariboldi K. Belt S. Smik L. Muschitiello F. Colizza E. Giglio F. Giordano P. Finocchiaro F. Morigi C. Capotondi L. Torricella F. Gallerani A. Tesi, T. Langone, L. Gariboldi, K. Belt, S. Smik, L. Muschitiello, F. Colizza, E. Giglio, F. Giordano, P. Finocchiaro, F. Morigi, C. Capotondi, L. Torricella, F. Gallerani, A. 2019 ELETTRONICO http://hdl.handle.net/11568/1035824 https://meetingorganizer.copernicus.org/EGU2019/EGU2019-11038-1.pdf eng eng volume:21 issue:EGU2019-11038-1 numberofpages:1 journal:GEOPHYSICAL RESEARCH ABSTRACTS http://hdl.handle.net/11568/1035824 https://meetingorganizer.copernicus.org/EGU2019/EGU2019-11038-1.pdf Sea-ice biomarker microfossils Ross Sea last 2ka info:eu-repo/semantics/article 2019 ftunivpisairis 2024-03-21T19:16:38Z We present data from a laminated sediment core collected in the Edisto inlet (Ross Sea, Antarctica). The expanded record (14.6 m long) covers the last ca. 2800 years and it is dominated by dark- and light-brown diatom oozes. We used a suite of proxies which include diatom assemblages, bulk OC and TN, nitrogen and carbon stable isotopes, opal, grain size and biomarker analyses with focus on the new IPSO-25 proxy (di-unsaturated highly branched isoprenoid) of landfast sea ice. A sub-sample of well-defined dark and light laminae (n=33) exhibited a statistically different (t-test) composition in terms of stable carbon isotopes, IPSO-25, relative percentage of the diatom Corethron pennatum, as well as porosity. Dark laminae are likely indicative of spring blooms when the delta-13C signature and IPSO-25 concen- tration are high, whereas porosity is comparatively low. The heavy delta-13C signature and high IPSO-25 values are consistent with deposition of sea-ice diatoms growing in reduced availability of dissolved inorganic carbon typical of sea-ice matrix. By contrast, the IPSO-25 in light laminae decreases by up to three-orders of magnitude together with a marked decrease of delta-13C. We interpret these trends to reflect a protracted opening of the bay later in summer and a greater availability of carbon for photosynthesis. Under these conditions, the greater Corethron pennatum concentration in the light-brown laminae might indicate a different environment likely asso- ciated with open water conditions. In addition, the relatively higher abundance of Corethron pennatum resulted in a “sponge-like” matrix which explains the marked difference in porosity between light and dark laminae. The same suite of parameters were then analysed throughout the sediment core (n=300). Spectral analysis of the core data revealed a pervasive and persistent cyclicity at ∼90 years consistent with the Gleissberg solar cycle. Based on the information gained from the laminae analysis, we infer that through a top-down effect solar activity ... Article in Journal/Newspaper Antarc* Antarctica Ross Sea Sea ice ARPI - Archivio della Ricerca dell'Università di Pisa Edisto ENVELOPE(-67.133,-67.133,-68.217,-68.217) Edisto Inlet ENVELOPE(170.083,170.083,-72.333,-72.333) Ross Sea |
institution |
Open Polar |
collection |
ARPI - Archivio della Ricerca dell'Università di Pisa |
op_collection_id |
ftunivpisairis |
language |
English |
topic |
Sea-ice biomarker microfossils Ross Sea last 2ka |
spellingShingle |
Sea-ice biomarker microfossils Ross Sea last 2ka Tesi T. Langone L. Gariboldi K. Belt S. Smik L. Muschitiello F. Colizza E. Giglio F. Giordano P. Finocchiaro F. Morigi C. Capotondi L. Torricella F. Gallerani A. Late-Holocene record of environmental changes in the Ross Sea: from seasonal to centennial time scales. |
topic_facet |
Sea-ice biomarker microfossils Ross Sea last 2ka |
description |
We present data from a laminated sediment core collected in the Edisto inlet (Ross Sea, Antarctica). The expanded record (14.6 m long) covers the last ca. 2800 years and it is dominated by dark- and light-brown diatom oozes. We used a suite of proxies which include diatom assemblages, bulk OC and TN, nitrogen and carbon stable isotopes, opal, grain size and biomarker analyses with focus on the new IPSO-25 proxy (di-unsaturated highly branched isoprenoid) of landfast sea ice. A sub-sample of well-defined dark and light laminae (n=33) exhibited a statistically different (t-test) composition in terms of stable carbon isotopes, IPSO-25, relative percentage of the diatom Corethron pennatum, as well as porosity. Dark laminae are likely indicative of spring blooms when the delta-13C signature and IPSO-25 concen- tration are high, whereas porosity is comparatively low. The heavy delta-13C signature and high IPSO-25 values are consistent with deposition of sea-ice diatoms growing in reduced availability of dissolved inorganic carbon typical of sea-ice matrix. By contrast, the IPSO-25 in light laminae decreases by up to three-orders of magnitude together with a marked decrease of delta-13C. We interpret these trends to reflect a protracted opening of the bay later in summer and a greater availability of carbon for photosynthesis. Under these conditions, the greater Corethron pennatum concentration in the light-brown laminae might indicate a different environment likely asso- ciated with open water conditions. In addition, the relatively higher abundance of Corethron pennatum resulted in a “sponge-like” matrix which explains the marked difference in porosity between light and dark laminae. The same suite of parameters were then analysed throughout the sediment core (n=300). Spectral analysis of the core data revealed a pervasive and persistent cyclicity at ∼90 years consistent with the Gleissberg solar cycle. Based on the information gained from the laminae analysis, we infer that through a top-down effect solar activity ... |
author2 |
Tesi, T. Langone, L. Gariboldi, K. Belt, S. Smik, L. Muschitiello, F. Colizza, E. Giglio, F. Giordano, P. Finocchiaro, F. Morigi, C. Capotondi, L. Torricella, F. Gallerani, A. |
format |
Article in Journal/Newspaper |
author |
Tesi T. Langone L. Gariboldi K. Belt S. Smik L. Muschitiello F. Colizza E. Giglio F. Giordano P. Finocchiaro F. Morigi C. Capotondi L. Torricella F. Gallerani A. |
author_facet |
Tesi T. Langone L. Gariboldi K. Belt S. Smik L. Muschitiello F. Colizza E. Giglio F. Giordano P. Finocchiaro F. Morigi C. Capotondi L. Torricella F. Gallerani A. |
author_sort |
Tesi T. |
title |
Late-Holocene record of environmental changes in the Ross Sea: from seasonal to centennial time scales. |
title_short |
Late-Holocene record of environmental changes in the Ross Sea: from seasonal to centennial time scales. |
title_full |
Late-Holocene record of environmental changes in the Ross Sea: from seasonal to centennial time scales. |
title_fullStr |
Late-Holocene record of environmental changes in the Ross Sea: from seasonal to centennial time scales. |
title_full_unstemmed |
Late-Holocene record of environmental changes in the Ross Sea: from seasonal to centennial time scales. |
title_sort |
late-holocene record of environmental changes in the ross sea: from seasonal to centennial time scales. |
publishDate |
2019 |
url |
http://hdl.handle.net/11568/1035824 https://meetingorganizer.copernicus.org/EGU2019/EGU2019-11038-1.pdf |
long_lat |
ENVELOPE(-67.133,-67.133,-68.217,-68.217) ENVELOPE(170.083,170.083,-72.333,-72.333) |
geographic |
Edisto Edisto Inlet Ross Sea |
geographic_facet |
Edisto Edisto Inlet Ross Sea |
genre |
Antarc* Antarctica Ross Sea Sea ice |
genre_facet |
Antarc* Antarctica Ross Sea Sea ice |
op_relation |
volume:21 issue:EGU2019-11038-1 numberofpages:1 journal:GEOPHYSICAL RESEARCH ABSTRACTS http://hdl.handle.net/11568/1035824 https://meetingorganizer.copernicus.org/EGU2019/EGU2019-11038-1.pdf |
_version_ |
1796299973544902656 |