Ester Colizza | University Of Trieste (original) (raw)

Papers by Ester Colizza

EGU General Assembly Conference Abstracts, Apr 1, 2016

Geosciences, 2021

The continental margin is a key area for studying the sedimentary processes related to the advanc... more The continental margin is a key area for studying the sedimentary processes related to the advance and retreat of the Ross Ice Shelf (Antarctica); nevertheless, much remains to be investigated. The aim of this study is to increase the knowledge of the last glacial/deglacial dynamics in the Central Basin slope–basin system using a multidisciplinary approach, including integrated sedimentological, micropaleontological and tephrochronological information. The analyses carried out on three box cores highlighted sedimentary sequences characterised by tree stratigraphic units. Collected sediments represent a time interval from 24 ka Before Present (BP) to the present time. Grain size clustering and data on the sortable silt component, together with diatom, silicoflagellate and foraminifera assemblages indicate the influence of the ice shelf calving zone (Unit 1, 24–17 ka BP), progressive receding due to Circumpolar Deep Water inflow (Unit 2, 17–10.2 ka BP) and (Unit 3, 10.2 ka BP–present)...

The EGU General Assembly, 2017

The EGU General Assembly, 2016

57 submarIne earthquaKe geology as a tool For seIsmIc hazard assessment In the calabrIan arc A. P... more 57 submarIne earthquaKe geology as a tool For seIsmIc hazard assessment In the calabrIan arc A. Polonia1, S. Romano1, L. Gasperini1, S.C. Vaiani2, G. Gasparotto2, E. Colizza3, L. Torelli4 1 Institute of Marine Sciences (ISMAR-CNR), Bologna, Italy 2 Dipartimento di Scienze Biologiche, Geologiche e Ambientali, University of Bologna, Italy 3 Dip. di Matematica e Geoscienze, Universita’ degli Studi di Trieste, Italy 4 Dipartimento di Fisica e Scienze della Terra “Macedonio Melloni”, University of Parma, Italy

Trieste "città della ricerca polare"? Di primo acchito si sarebbe tentati di respingere con un so... more Trieste "città della ricerca polare"? Di primo acchito si sarebbe tentati di respingere con un sorriso, se non con una battuta, questa idea. Una città che s'apre su un mare baciato dal sole qual è l'Adriatico, come potrebbe avere un collegamento con le ghiacciate regioni polari, così distanti non solo geograficamente ma anche per clima, storia, popoli e cultura? E anche volendo ammettere un interesse dei triestini, o dei giuliani in generale, per quelle lande desolate, come potrebbero delle persone nate e vissute in un clima temperato affrontare gli strapazzi propri di un'impresa polare, o anche semplicemente sopravvivere, in regioni dove la temperatura scende anche al di sotto dei-50 °C e la notte dura mesi interi? 1 Inizia così l'Introduzione alla nuova edizione del volume Trieste fra i ghiacci di Enrico Mazzoli-edito da Luglio Editore-che ripercorre, in modo dettagliato e con un tocco personale, le tappe che hanno proiettato la città di Trieste e i suoi ricercatori nell'avventura polare, narrando le storie dei protagonisti delle spedizioni tra i ghiacci a partire dall'Ottocento fino ai giorni nostri. L'uscita del volume che, in realtà, è la nuova edizione di un libro pubblicato nel 2012, è stata l'occasione per proporre una conferenza dal titolo "Da Trieste ai Poli: i viaggi che hanno portato la ricerca triestina agli estremi del pianeta", che si è svolta il 31 ottobre scorso nell'ambito di Trieste e la Scienza-mostra interattiva e multimediale, allestita presso la stazione ferroviaria di Trieste nello spazio gestito dallo SISSA MediaLab 2 dedicato a "Trieste città della conoscenza" 3. Alla conferenza, oltre a Enrico Mazzoli, autore del volume, sono intervenute Laura De Santis, ricercatrice dell'OGS-Istituto Nazionale di Oceanografia e di Geofisica * Title: Chronicle.

In order to understand the growth and retreat of glaciers in response to the glacial-interglacial... more In order to understand the growth and retreat of glaciers in response to the glacial-interglacial changes, subglacial marine sedimentary sequences have been studied extensively in the continental shelf areas of the Ross Sea. The purpose is to comprehend the glaciomarine sedimentation change on the continental slope of eastern Pennell-Iselin Bank in the Ross Sea, using three gravity cores (C1, C2, C3) and three box cores (BC1, BC2, BC3) collected from sites (RS14-1, 2, 3), respectively, across the continental slope to the eastern side of the Pennell-Iselin Bank during XXIX° (2014) PNRA expedition (Rosslope Ⅱ project). Several sedimentological (grain size, magnetic susceptibility), elemental (XRF), geochemical (biogenic opal, total organic carbon, total nitrogen, C/N ratios, CaCO3), and isotopic (δ13C and δ15N of organic matter) parameters were measured along sediment cores with AMS 14C dating of bulk sediments. Core-sediments consist mostly of hemipelagic sandy clay or silty clay wit...

Journal of Micropalaeontology, 2021

During the Late Pleistocene-Holocene, the Ross Sea Ice Shelf exhibited strong spatial variability... more During the Late Pleistocene-Holocene, the Ross Sea Ice Shelf exhibited strong spatial variability in relation to the atmospheric and oceanographic climatic variations. Despite being thoroughly investigated, the timing of the ice sheet retreat from the outer continental shelf since the Last Glacial Maximum (LGM) still remains controversial, mainly due to a lack of sediment cores with a robust chronostratigraphy. For this reason, the recent recovery of sediments containing a continuous occurrence of calcareous foraminifera provides the important opportunity to create a reliable age model and document the early deglacial phase in particular. Here we present a multiproxy study from a sediment core collected at the Hallett Ridge (1800 m of depth), where significant occurrences of calcareous planktonic and benthic foraminifera allow us to document the first evidence of the deglaciation after the LGM at about 20.2 ka. Our results suggest that the co-occurrence of large Neogloboquadrina pachyderma tests and abundant juvenile forms reflects the beginning of open-water conditions and coverage of seasonal sea ice. Our multiproxy approach based on diatoms, silicoflagellates, carbon and oxygen stable isotopes on N. pachyderma, sediment texture, and geochemistry indicates that abrupt warming occurred at approximately 17.8 ka, followed by a period of increasing biological productivity. During the Holocene, the exclusive dominance of agglutinated benthic foraminifera suggests that dissolution was the main controlling factor on calcareous test accumulation and preservation. Diatoms and silicoflagellates show that ocean conditions were variable during the middle Holocene and the beginning of the Neoglacial period at around 4 ka. In the Neoglacial, an increase in sand content testifies to a strengthening of bottom-water currents, supported by an increase in the abundance of the tycopelagic fossil diatom Paralia sulcata transported from the coastal regions, while an increase in ice-rafted debris suggests more glacial transport by icebergs.

Geomorphology, 2021

Increased ocean heat supply to the Antarctic continental shelves is projected to cause accelerate... more Increased ocean heat supply to the Antarctic continental shelves is projected to cause accelerated ice sheet loss and contribute significantly to global sea-level rise over coming decades. Changes in temperature or salinity of dense shelf waters around Antarctica, resulting from increased glacial meltwater input, have the potential to significantly impact the location and structure of the global Meridional Overturning Circulation, with seabed irregularities such as submarine canyons, driving these flows toward the abyss. Submarine canyons also influence the location of intruding warm water currents by acting as preferential routes for rising Circumpolar Deep Water. These global changes have implications for large-scale effects to atmospheric and oceanic circulation. The ability for numerical modellers to predict these future behaviours is dependent upon our ability to understand both modern and past oceanic, sedimentological and glaciological processes. This knowledge allows ocean models to better predict the flux and pathways of Circumpolar Deep Water delivery to the shelf, and consequently to ice shelf cavities where melt is concentrated. Here we seek to understand how dense shelf water and other continental slope processes influence submarine canyon morphology by analysing newly Accepted 28th September 2020 2 collected geophysical and oceanographic data from a region of significant and prolonged dense shelf water export, the Hillary Canyon in the Ross Sea. We find that cascading flows of dense shelf water do not contribute to significant gully incision at the shelf edge during interglacial periods, however, are strong enough to prevent gully infilling and contribute to canyon-levee aggradation down-slope. We find buried paleo-gullies beneath gullies incising the modern seafloor. Paleo-gullies occur as single gullies and in complexes indicating that gully activity was continuous over multiple glacial cycles and formed an important role in the development of the shelf edge and upper slope. Glacial cycles likely drive large-scale shifts in canyon head processes with periods of intense seafloor erosion and significant gully incision likely occurring when ice grounded near to the shelf edge, during glacial and deglacial periods, when sediment-laden subglacial meltwater was released at the shelf edge. We put slope morphology observed at the Hillary Canyon head into global perspective to show that cascading flows of dense shelf water do not exert consistent patterns of erosion on high-latitude continental margins. 2. Introduction Increased ocean heat supply to Antarctic continental shelves is projected to cause accelerated ice sheet loss and contribute significantly to global sea-level rise over coming decades to centuries (De Conto et al., 2016; IPCC, 2019). Currently, numerical modelling studies lack necessary resolution and spatial coverage of seafloor morphology data to sufficiently constrain past and future sub-ice shelf melting, ice-sheet collapse, and sea level change estimates (Petrini et al., 2018; Colleoni et al., 2018). This is because one of the major causes of current Antarctic ice sheet retreat stems from increased ocean heat supply to the continental shelves surrounding Antarctica, with atmospheric temperature rise contributing to a lesser extent (Rignot et al., 2019; IPCC, 2019). Recent studies show that heat and volume transport around Antarctica are substantially enhanced where seafloor irregularities, such as submarine canyons, allow dense shelf waters to descend down-slope (Morrison et al., 2020). Warm water incursions onto the shelf can be intermittent and highly localised and can vary depending on the geometry of the ice shelf and seafloor bathymetry (Padman et al., 2018). Lack of necessary resolution and data availability to image these irregularities therefore makes predictions and future estimates of ice sheet and oceanic changes difficult. Thinning of ice shelves, due to increasing ocean temperatures and warm water incursions can lead to rapid ice retreat. This is especially true where marine based ice-sheets occur in conjunction with a landward sloping seabed, seen around the West and East Antarctic Ice Sheet (WAIS and

Quaternary Science Reviews, 2020

This is a pre-publication version. Readers are recommended to consult the full published version ... more This is a pre-publication version. Readers are recommended to consult the full published version for accuracy and citation." Ross Sea. Our study has shown that multi-proxy data derived from laminated sediments can provide hitherto unknown detail regarding past summer sea ice dynamics in coastal Antarctic regions.

Quaternary Science Reviews, 2020

In Antarctica, the near-source exposures of volcanic eruption deposits are often limited as they ... more In Antarctica, the near-source exposures of volcanic eruption deposits are often limited as they are not well preserved in the dynamic glacial environment, thus making volcanological reconstructions of explosive eruptions extremely challenging. Fortunately, pyroclastic deposits from explosive eruptions are preserved in Southern Ocean sediments surrounding Antarctica, and the tephrostratigraphy of these sequences offers crucial volcanological information including the timing and tempo of past eruptions, their magnitude, and eruption dynamics. Here we report the results of a

Chemosphere, 2017

 Sea salt sodium at Talos Dome can be used as a reliable proxy of sea ice extent.  A positive r... more  Sea salt sodium at Talos Dome can be used as a reliable proxy of sea ice extent.  A positive relationship between ssNa + flux and SIE maxima was found.  SIE of the Ross Sea and Western Pacific was reconstructed over the 20 th century  SIE variability increased starting from 1990s.

Biogeographia – The Journal of Integrative Biogeography, 1989

Geological disciplines are increasingly applied to archaeological research. Their potentialities ... more Geological disciplines are increasingly applied to archaeological research. Their potentialities are able to cover numerous fields of research, since they can become very interesting tools to define the ancient environments, the origin of the human settlements and the natural and anthropic processes which occurred through the evolution of the territory. Elaiussa Sebaste (Mersin region, South-Eastern coast of the Turkey), which was an important coastal town from the II century BC to VII century AD, may represent a noteworthy field of application of geological disciplines. This site was one of the main trading harbours of the Mediterranean (from the Augustan to the Byzantine era) growing in the Augustan period and maintaining its prestige until the late Empire and the Byzantine era. Actually it was the intersection of the most important shipping and land routes among Syria, Egypt and the Anatolian peninsula. The evolution of the coastal environment around this town has been continuously modified by men along its history. The most evident modification occurred North and South the promontory of Elaiussa-Sebaste bay, i.e. the construction of two harbours, which have been subsequently buried by not well defined events. The definition of the geological processes controlling the evolution of the coastal area during the last 3000 years, should become essential to reconstruct the succession of the palaeoenvironments of Elaiussa Sebaste, including the decline of the harbours.With regard to this topic, the geomorphologic analysis reveals the complex interactions among tectonics, erosion and sedimentation in this coastal area in both, emerged and in ancient times submerged settings facing the archaeological site. During the summer 2012, a geological survey allowed us to drill nine boreholes along the land-to-sea transects in both harbours. Preliminary observations indicate the stratigraphic evolution from restricted to open marine coastal environments. Sedimentology, palaeontology, palynology and sediment geochemistry are applied to study the stratigraphical sequences of boreholes and archaeological excavations. We plan obtain an evolutionary model which might consist of natural (pre-harbour) deposits, covered by low hydrodynamic sediments, which were deposited in the harbour \u201ccontainer\u201d, and finally overlaid by other ones responsible of the harbours burial. Radiocarbon dating will precisely define the chronology of these events. We emphasize the role of the palynological analyses which will be addressed to the reconstruction of the evolution of the vegetation, identifying its climatic/environmental changes through the time, also in relation with the human activities in the site

Bulletin of Volcanology, 2015

ABSTRACT High latitudes are particularly interesting places to document natural climate variabili... more ABSTRACT High latitudes are particularly interesting places to document natural climate variability. Sea ice is an important element in the climate system because it influences bottom water formation and ocean circulation and regulates the ocean-atmosphere heat exchange. Understanding climate and environmental changes through the reconstruction of past sea ice variability, atmospheric circulation and oceanographic conditions in the Southern Ocean could represent one of the most important keys to predict with confidence future climate changes on global scale. In fact, the oceanic area surrounding Antarctica represents the main source of bottom water formation affecting the global climate through the oceanic circulation. In this study, we present an interdisciplinary proxies analysis considering marine and ice core records, as part of the ESF PolarCLIMATE HOLOCLIP (Holocene climate variability at high-southern latitudes: an integrated perspective) project, to document sea ice variability in the Ross Sea continental shelf area. Diatom assemblages from three sediment cores located in the north-western Ross Sea (Joides Basin, Cape Hallett and Wood Bay) have been studied and the sea salt Na+ (a potential proxy of sea ice) records from two ice core sites (Taylor Dome and Talos Dome) facing the Ross Sea area have been considered. The significant positive correlations among the sea ice diatom Fragilariopsis curta relative abundance and sea salt Na+ records from Talos Dome and Taylor Dome ice cores, suggest that sea salt Na+ could be used as a proxy for sea ice extent and/or duration in the Ross Sea area. These preliminary results look as a positive premise in view of integrating proxies from different realms (marine and glacial) in order to achieve a more complete view of the climate and environmental changes occurring during the Holocene. The combination of geological and glacial records will greatly improve our knowledge on paleo sea ice dynamics.

Sediment cores and box cores collected in two coastal areas of the northwestern Ross Sea (Antarct... more Sediment cores and box cores collected in two coastal areas of the northwestern Ross Sea (Antarctica) highlight the possibility of studying the Late Holocene period in detail. In this work we propose a study on two box cores and two gravity cores collected in the Cape Hallett and Wood Bay areas during the 2005 PNRA oceanographic cruise. The two sites are feed by Eastern Antarctic Ice Shelf (EAIS) and previous studies have highlighted a complex postglacial sedimentary sequence, also influenced by local morphology. This study is performed within the framework of the PNRA-ESF PolarCLIMATE HOLOCLIP (Holocene climate variability at high-southern latitudes: an integrated perspective) Project. The data set includes: magnetic susceptibility, X-ray analyses, 210Pb, 14C dating, diatoms and foraminifera assemblages, organic carbon, and grain-size analyses. Furthermore XRF core scanner analyses, colour analysis from digital images, and major, minor and trace element concentration analyses (ICP-AES) are performed. Data show that the box core and upper core sediments represent a very recent sedimentation in which it is possible to observe the parameter variability probably linked to climate variability/changes: these variation will be compared with isotopic record form ice cores collected form the same Antarctic sector.

EGU General Assembly Conference Abstracts, Apr 1, 2016

Geosciences, 2021

The continental margin is a key area for studying the sedimentary processes related to the advanc... more The continental margin is a key area for studying the sedimentary processes related to the advance and retreat of the Ross Ice Shelf (Antarctica); nevertheless, much remains to be investigated. The aim of this study is to increase the knowledge of the last glacial/deglacial dynamics in the Central Basin slope–basin system using a multidisciplinary approach, including integrated sedimentological, micropaleontological and tephrochronological information. The analyses carried out on three box cores highlighted sedimentary sequences characterised by tree stratigraphic units. Collected sediments represent a time interval from 24 ka Before Present (BP) to the present time. Grain size clustering and data on the sortable silt component, together with diatom, silicoflagellate and foraminifera assemblages indicate the influence of the ice shelf calving zone (Unit 1, 24–17 ka BP), progressive receding due to Circumpolar Deep Water inflow (Unit 2, 17–10.2 ka BP) and (Unit 3, 10.2 ka BP–present)...

The EGU General Assembly, 2017

The EGU General Assembly, 2016

57 submarIne earthquaKe geology as a tool For seIsmIc hazard assessment In the calabrIan arc A. P... more 57 submarIne earthquaKe geology as a tool For seIsmIc hazard assessment In the calabrIan arc A. Polonia1, S. Romano1, L. Gasperini1, S.C. Vaiani2, G. Gasparotto2, E. Colizza3, L. Torelli4 1 Institute of Marine Sciences (ISMAR-CNR), Bologna, Italy 2 Dipartimento di Scienze Biologiche, Geologiche e Ambientali, University of Bologna, Italy 3 Dip. di Matematica e Geoscienze, Universita’ degli Studi di Trieste, Italy 4 Dipartimento di Fisica e Scienze della Terra “Macedonio Melloni”, University of Parma, Italy

Trieste "città della ricerca polare"? Di primo acchito si sarebbe tentati di respingere con un so... more Trieste "città della ricerca polare"? Di primo acchito si sarebbe tentati di respingere con un sorriso, se non con una battuta, questa idea. Una città che s'apre su un mare baciato dal sole qual è l'Adriatico, come potrebbe avere un collegamento con le ghiacciate regioni polari, così distanti non solo geograficamente ma anche per clima, storia, popoli e cultura? E anche volendo ammettere un interesse dei triestini, o dei giuliani in generale, per quelle lande desolate, come potrebbero delle persone nate e vissute in un clima temperato affrontare gli strapazzi propri di un'impresa polare, o anche semplicemente sopravvivere, in regioni dove la temperatura scende anche al di sotto dei-50 °C e la notte dura mesi interi? 1 Inizia così l'Introduzione alla nuova edizione del volume Trieste fra i ghiacci di Enrico Mazzoli-edito da Luglio Editore-che ripercorre, in modo dettagliato e con un tocco personale, le tappe che hanno proiettato la città di Trieste e i suoi ricercatori nell'avventura polare, narrando le storie dei protagonisti delle spedizioni tra i ghiacci a partire dall'Ottocento fino ai giorni nostri. L'uscita del volume che, in realtà, è la nuova edizione di un libro pubblicato nel 2012, è stata l'occasione per proporre una conferenza dal titolo "Da Trieste ai Poli: i viaggi che hanno portato la ricerca triestina agli estremi del pianeta", che si è svolta il 31 ottobre scorso nell'ambito di Trieste e la Scienza-mostra interattiva e multimediale, allestita presso la stazione ferroviaria di Trieste nello spazio gestito dallo SISSA MediaLab 2 dedicato a "Trieste città della conoscenza" 3. Alla conferenza, oltre a Enrico Mazzoli, autore del volume, sono intervenute Laura De Santis, ricercatrice dell'OGS-Istituto Nazionale di Oceanografia e di Geofisica * Title: Chronicle.

In order to understand the growth and retreat of glaciers in response to the glacial-interglacial... more In order to understand the growth and retreat of glaciers in response to the glacial-interglacial changes, subglacial marine sedimentary sequences have been studied extensively in the continental shelf areas of the Ross Sea. The purpose is to comprehend the glaciomarine sedimentation change on the continental slope of eastern Pennell-Iselin Bank in the Ross Sea, using three gravity cores (C1, C2, C3) and three box cores (BC1, BC2, BC3) collected from sites (RS14-1, 2, 3), respectively, across the continental slope to the eastern side of the Pennell-Iselin Bank during XXIX° (2014) PNRA expedition (Rosslope Ⅱ project). Several sedimentological (grain size, magnetic susceptibility), elemental (XRF), geochemical (biogenic opal, total organic carbon, total nitrogen, C/N ratios, CaCO3), and isotopic (δ13C and δ15N of organic matter) parameters were measured along sediment cores with AMS 14C dating of bulk sediments. Core-sediments consist mostly of hemipelagic sandy clay or silty clay wit...

Journal of Micropalaeontology, 2021

During the Late Pleistocene-Holocene, the Ross Sea Ice Shelf exhibited strong spatial variability... more During the Late Pleistocene-Holocene, the Ross Sea Ice Shelf exhibited strong spatial variability in relation to the atmospheric and oceanographic climatic variations. Despite being thoroughly investigated, the timing of the ice sheet retreat from the outer continental shelf since the Last Glacial Maximum (LGM) still remains controversial, mainly due to a lack of sediment cores with a robust chronostratigraphy. For this reason, the recent recovery of sediments containing a continuous occurrence of calcareous foraminifera provides the important opportunity to create a reliable age model and document the early deglacial phase in particular. Here we present a multiproxy study from a sediment core collected at the Hallett Ridge (1800 m of depth), where significant occurrences of calcareous planktonic and benthic foraminifera allow us to document the first evidence of the deglaciation after the LGM at about 20.2 ka. Our results suggest that the co-occurrence of large Neogloboquadrina pachyderma tests and abundant juvenile forms reflects the beginning of open-water conditions and coverage of seasonal sea ice. Our multiproxy approach based on diatoms, silicoflagellates, carbon and oxygen stable isotopes on N. pachyderma, sediment texture, and geochemistry indicates that abrupt warming occurred at approximately 17.8 ka, followed by a period of increasing biological productivity. During the Holocene, the exclusive dominance of agglutinated benthic foraminifera suggests that dissolution was the main controlling factor on calcareous test accumulation and preservation. Diatoms and silicoflagellates show that ocean conditions were variable during the middle Holocene and the beginning of the Neoglacial period at around 4 ka. In the Neoglacial, an increase in sand content testifies to a strengthening of bottom-water currents, supported by an increase in the abundance of the tycopelagic fossil diatom Paralia sulcata transported from the coastal regions, while an increase in ice-rafted debris suggests more glacial transport by icebergs.

Geomorphology, 2021

Increased ocean heat supply to the Antarctic continental shelves is projected to cause accelerate... more Increased ocean heat supply to the Antarctic continental shelves is projected to cause accelerated ice sheet loss and contribute significantly to global sea-level rise over coming decades. Changes in temperature or salinity of dense shelf waters around Antarctica, resulting from increased glacial meltwater input, have the potential to significantly impact the location and structure of the global Meridional Overturning Circulation, with seabed irregularities such as submarine canyons, driving these flows toward the abyss. Submarine canyons also influence the location of intruding warm water currents by acting as preferential routes for rising Circumpolar Deep Water. These global changes have implications for large-scale effects to atmospheric and oceanic circulation. The ability for numerical modellers to predict these future behaviours is dependent upon our ability to understand both modern and past oceanic, sedimentological and glaciological processes. This knowledge allows ocean models to better predict the flux and pathways of Circumpolar Deep Water delivery to the shelf, and consequently to ice shelf cavities where melt is concentrated. Here we seek to understand how dense shelf water and other continental slope processes influence submarine canyon morphology by analysing newly Accepted 28th September 2020 2 collected geophysical and oceanographic data from a region of significant and prolonged dense shelf water export, the Hillary Canyon in the Ross Sea. We find that cascading flows of dense shelf water do not contribute to significant gully incision at the shelf edge during interglacial periods, however, are strong enough to prevent gully infilling and contribute to canyon-levee aggradation down-slope. We find buried paleo-gullies beneath gullies incising the modern seafloor. Paleo-gullies occur as single gullies and in complexes indicating that gully activity was continuous over multiple glacial cycles and formed an important role in the development of the shelf edge and upper slope. Glacial cycles likely drive large-scale shifts in canyon head processes with periods of intense seafloor erosion and significant gully incision likely occurring when ice grounded near to the shelf edge, during glacial and deglacial periods, when sediment-laden subglacial meltwater was released at the shelf edge. We put slope morphology observed at the Hillary Canyon head into global perspective to show that cascading flows of dense shelf water do not exert consistent patterns of erosion on high-latitude continental margins. 2. Introduction Increased ocean heat supply to Antarctic continental shelves is projected to cause accelerated ice sheet loss and contribute significantly to global sea-level rise over coming decades to centuries (De Conto et al., 2016; IPCC, 2019). Currently, numerical modelling studies lack necessary resolution and spatial coverage of seafloor morphology data to sufficiently constrain past and future sub-ice shelf melting, ice-sheet collapse, and sea level change estimates (Petrini et al., 2018; Colleoni et al., 2018). This is because one of the major causes of current Antarctic ice sheet retreat stems from increased ocean heat supply to the continental shelves surrounding Antarctica, with atmospheric temperature rise contributing to a lesser extent (Rignot et al., 2019; IPCC, 2019). Recent studies show that heat and volume transport around Antarctica are substantially enhanced where seafloor irregularities, such as submarine canyons, allow dense shelf waters to descend down-slope (Morrison et al., 2020). Warm water incursions onto the shelf can be intermittent and highly localised and can vary depending on the geometry of the ice shelf and seafloor bathymetry (Padman et al., 2018). Lack of necessary resolution and data availability to image these irregularities therefore makes predictions and future estimates of ice sheet and oceanic changes difficult. Thinning of ice shelves, due to increasing ocean temperatures and warm water incursions can lead to rapid ice retreat. This is especially true where marine based ice-sheets occur in conjunction with a landward sloping seabed, seen around the West and East Antarctic Ice Sheet (WAIS and

Quaternary Science Reviews, 2020

This is a pre-publication version. Readers are recommended to consult the full published version ... more This is a pre-publication version. Readers are recommended to consult the full published version for accuracy and citation." Ross Sea. Our study has shown that multi-proxy data derived from laminated sediments can provide hitherto unknown detail regarding past summer sea ice dynamics in coastal Antarctic regions.

Quaternary Science Reviews, 2020

In Antarctica, the near-source exposures of volcanic eruption deposits are often limited as they ... more In Antarctica, the near-source exposures of volcanic eruption deposits are often limited as they are not well preserved in the dynamic glacial environment, thus making volcanological reconstructions of explosive eruptions extremely challenging. Fortunately, pyroclastic deposits from explosive eruptions are preserved in Southern Ocean sediments surrounding Antarctica, and the tephrostratigraphy of these sequences offers crucial volcanological information including the timing and tempo of past eruptions, their magnitude, and eruption dynamics. Here we report the results of a

Chemosphere, 2017

 Sea salt sodium at Talos Dome can be used as a reliable proxy of sea ice extent.  A positive r... more  Sea salt sodium at Talos Dome can be used as a reliable proxy of sea ice extent.  A positive relationship between ssNa + flux and SIE maxima was found.  SIE of the Ross Sea and Western Pacific was reconstructed over the 20 th century  SIE variability increased starting from 1990s.

Biogeographia – The Journal of Integrative Biogeography, 1989

Geological disciplines are increasingly applied to archaeological research. Their potentialities ... more Geological disciplines are increasingly applied to archaeological research. Their potentialities are able to cover numerous fields of research, since they can become very interesting tools to define the ancient environments, the origin of the human settlements and the natural and anthropic processes which occurred through the evolution of the territory. Elaiussa Sebaste (Mersin region, South-Eastern coast of the Turkey), which was an important coastal town from the II century BC to VII century AD, may represent a noteworthy field of application of geological disciplines. This site was one of the main trading harbours of the Mediterranean (from the Augustan to the Byzantine era) growing in the Augustan period and maintaining its prestige until the late Empire and the Byzantine era. Actually it was the intersection of the most important shipping and land routes among Syria, Egypt and the Anatolian peninsula. The evolution of the coastal environment around this town has been continuously modified by men along its history. The most evident modification occurred North and South the promontory of Elaiussa-Sebaste bay, i.e. the construction of two harbours, which have been subsequently buried by not well defined events. The definition of the geological processes controlling the evolution of the coastal area during the last 3000 years, should become essential to reconstruct the succession of the palaeoenvironments of Elaiussa Sebaste, including the decline of the harbours.With regard to this topic, the geomorphologic analysis reveals the complex interactions among tectonics, erosion and sedimentation in this coastal area in both, emerged and in ancient times submerged settings facing the archaeological site. During the summer 2012, a geological survey allowed us to drill nine boreholes along the land-to-sea transects in both harbours. Preliminary observations indicate the stratigraphic evolution from restricted to open marine coastal environments. Sedimentology, palaeontology, palynology and sediment geochemistry are applied to study the stratigraphical sequences of boreholes and archaeological excavations. We plan obtain an evolutionary model which might consist of natural (pre-harbour) deposits, covered by low hydrodynamic sediments, which were deposited in the harbour \u201ccontainer\u201d, and finally overlaid by other ones responsible of the harbours burial. Radiocarbon dating will precisely define the chronology of these events. We emphasize the role of the palynological analyses which will be addressed to the reconstruction of the evolution of the vegetation, identifying its climatic/environmental changes through the time, also in relation with the human activities in the site

Bulletin of Volcanology, 2015

ABSTRACT High latitudes are particularly interesting places to document natural climate variabili... more ABSTRACT High latitudes are particularly interesting places to document natural climate variability. Sea ice is an important element in the climate system because it influences bottom water formation and ocean circulation and regulates the ocean-atmosphere heat exchange. Understanding climate and environmental changes through the reconstruction of past sea ice variability, atmospheric circulation and oceanographic conditions in the Southern Ocean could represent one of the most important keys to predict with confidence future climate changes on global scale. In fact, the oceanic area surrounding Antarctica represents the main source of bottom water formation affecting the global climate through the oceanic circulation. In this study, we present an interdisciplinary proxies analysis considering marine and ice core records, as part of the ESF PolarCLIMATE HOLOCLIP (Holocene climate variability at high-southern latitudes: an integrated perspective) project, to document sea ice variability in the Ross Sea continental shelf area. Diatom assemblages from three sediment cores located in the north-western Ross Sea (Joides Basin, Cape Hallett and Wood Bay) have been studied and the sea salt Na+ (a potential proxy of sea ice) records from two ice core sites (Taylor Dome and Talos Dome) facing the Ross Sea area have been considered. The significant positive correlations among the sea ice diatom Fragilariopsis curta relative abundance and sea salt Na+ records from Talos Dome and Taylor Dome ice cores, suggest that sea salt Na+ could be used as a proxy for sea ice extent and/or duration in the Ross Sea area. These preliminary results look as a positive premise in view of integrating proxies from different realms (marine and glacial) in order to achieve a more complete view of the climate and environmental changes occurring during the Holocene. The combination of geological and glacial records will greatly improve our knowledge on paleo sea ice dynamics.

Sediment cores and box cores collected in two coastal areas of the northwestern Ross Sea (Antarct... more Sediment cores and box cores collected in two coastal areas of the northwestern Ross Sea (Antarctica) highlight the possibility of studying the Late Holocene period in detail. In this work we propose a study on two box cores and two gravity cores collected in the Cape Hallett and Wood Bay areas during the 2005 PNRA oceanographic cruise. The two sites are feed by Eastern Antarctic Ice Shelf (EAIS) and previous studies have highlighted a complex postglacial sedimentary sequence, also influenced by local morphology. This study is performed within the framework of the PNRA-ESF PolarCLIMATE HOLOCLIP (Holocene climate variability at high-southern latitudes: an integrated perspective) Project. The data set includes: magnetic susceptibility, X-ray analyses, 210Pb, 14C dating, diatoms and foraminifera assemblages, organic carbon, and grain-size analyses. Furthermore XRF core scanner analyses, colour analysis from digital images, and major, minor and trace element concentration analyses (ICP-AES) are performed. Data show that the box core and upper core sediments represent a very recent sedimentation in which it is possible to observe the parameter variability probably linked to climate variability/changes: these variation will be compared with isotopic record form ice cores collected form the same Antarctic sector.