Wilkes Land Glacial History (WEGA)
A collaborative Italian/Australian marine geoscience research voyage to the George Vth Land sector of the East Antarctic continental margin was carried out between 11th February and 20th March, 2000, on board the of the RV Tangaroa. The cost of the expedition was shared jointly by the Italian and Au...
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Australian Antarctic Data Centre
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Online Access: | https://researchdata.ands.org.au/wilkes-land-glacial-history-wega/699373 https://data.aad.gov.au/metadata/records/ASAC_1044 |
id |
ftands:oai:ands.org.au::699373 |
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record_format |
openpolar |
institution |
Open Polar |
collection |
Research Data Australia (Australian National Data Service - ANDS) |
op_collection_id |
ftands |
language |
unknown |
topic |
climatologyMeteorologyAtmosphere elevation geoscientificInformation oceans SEAFLOOR TOPOGRAPHY EARTH SCIENCE BATHYMETRY/SEAFLOOR TOPOGRAPHY WATER DEPTH SEDIMENT TRANSPORT COASTAL PROCESSES SEDIMENTATION CONTINENTAL MARGINS SEDIMENT COMPOSITION MARINE SEDIMENTS STRATIGRAPHIC SEQUENCE TERRIGENOUS SEDIMENTS TURBIDITY OCEAN CURRENTS OCEAN CIRCULATION THERMOHALINE CIRCULATION WATER TEMPERATURE OCEAN TEMPERATURE CONDUCTIVITY SALINITY/DENSITY MICROFOSSILS PALEOCLIMATE OCEAN/LAKE RECORDS PALEOMAGNETIC DATA RADIOCARBON SEDIMENTS SEISMIC PROFILE SOLID EARTH TECTONICS EARTHQUAKES WEGA seismic Cenozoic R/V TANGAROA Paleo Start Date Paleo Stop Date PHANEROZOIC > OCEAN > SOUTHERN OCEAN GEOGRAPHIC REGION > POLAR |
spellingShingle |
climatologyMeteorologyAtmosphere elevation geoscientificInformation oceans SEAFLOOR TOPOGRAPHY EARTH SCIENCE BATHYMETRY/SEAFLOOR TOPOGRAPHY WATER DEPTH SEDIMENT TRANSPORT COASTAL PROCESSES SEDIMENTATION CONTINENTAL MARGINS SEDIMENT COMPOSITION MARINE SEDIMENTS STRATIGRAPHIC SEQUENCE TERRIGENOUS SEDIMENTS TURBIDITY OCEAN CURRENTS OCEAN CIRCULATION THERMOHALINE CIRCULATION WATER TEMPERATURE OCEAN TEMPERATURE CONDUCTIVITY SALINITY/DENSITY MICROFOSSILS PALEOCLIMATE OCEAN/LAKE RECORDS PALEOMAGNETIC DATA RADIOCARBON SEDIMENTS SEISMIC PROFILE SOLID EARTH TECTONICS EARTHQUAKES WEGA seismic Cenozoic R/V TANGAROA Paleo Start Date Paleo Stop Date PHANEROZOIC > OCEAN > SOUTHERN OCEAN GEOGRAPHIC REGION > POLAR Wilkes Land Glacial History (WEGA) |
topic_facet |
climatologyMeteorologyAtmosphere elevation geoscientificInformation oceans SEAFLOOR TOPOGRAPHY EARTH SCIENCE BATHYMETRY/SEAFLOOR TOPOGRAPHY WATER DEPTH SEDIMENT TRANSPORT COASTAL PROCESSES SEDIMENTATION CONTINENTAL MARGINS SEDIMENT COMPOSITION MARINE SEDIMENTS STRATIGRAPHIC SEQUENCE TERRIGENOUS SEDIMENTS TURBIDITY OCEAN CURRENTS OCEAN CIRCULATION THERMOHALINE CIRCULATION WATER TEMPERATURE OCEAN TEMPERATURE CONDUCTIVITY SALINITY/DENSITY MICROFOSSILS PALEOCLIMATE OCEAN/LAKE RECORDS PALEOMAGNETIC DATA RADIOCARBON SEDIMENTS SEISMIC PROFILE SOLID EARTH TECTONICS EARTHQUAKES WEGA seismic Cenozoic R/V TANGAROA Paleo Start Date Paleo Stop Date PHANEROZOIC > OCEAN > SOUTHERN OCEAN GEOGRAPHIC REGION > POLAR |
description |
A collaborative Italian/Australian marine geoscience research voyage to the George Vth Land sector of the East Antarctic continental margin was carried out between 11th February and 20th March, 2000, on board the of the RV Tangaroa. The cost of the expedition was shared jointly by the Italian and Australian National Antarctic Research Programs. Twenty four scientific personnel from 13 institutions participated in the expedition. The geophysical data collected includes a total of 1827 km of multi-channel seismic data and 562 km of Chirper sonar data. A total of 11 gravity cores, 28 piston cores, 18 surface grabs and 11 short trigger cores were collected on the voyage. Water profile (CTD) measurements and water samples were collected at nine stations and seabed bottom photographs were made at 11 stations. The expedition discovered and mapped a shelf sediment drift deposit covering about 400 km2 lying in an greater than 800m deep section of the George Vth basin west of the Mertz Glacier. It is a true 'drift' deposit, since these sediments exhibit a patchy distribution, large-scale bedforms, contain foreset bedding and display a depositional architecture indicative of contour-parallel sediment transport. A significant observation is that the drift thins to the north into an acoustically-transparent veneer; this observation implies that the drift is sourced from the outer continental shelf, with sediment being transported landwards, across the shelf and into an 850m deep inner shelf basin. The 'Mertz Drift' is over 35 m thick and core samples demonstrate that it is composed of laminated, anoxic, gelatinous olive green, silicious mud and diatom ooze (SMO). Preliminary shipboard counts of the laminae suggest a thickness of from 4 to 20mm, with a mean of about 7mm. While the lower sediments are laminated, there is a 20 to 50cm thick sandy drape at the surface over the whole of the drift. This suggests that a recent (late Holocene) change in the depositional environment has occurred, possibly related to changes in the extent of the nearby Mertz Glacier tongue, current regime and/or to the persistence of sea ice over the shelf area. Multi-channel seismic data show the occurrence of foreset beds at the shelf break, interpreted as having been deposited by ice streams that grounded on the outer shelf during glacial maxima. On the shelf, the seismic character of the seafloor exhibits highly reflective, parabolic reflectors suggestive of crystalline basement, cropping out at the seafloor. Northwards of these basement outcrops, the water depth increases to over 1,100 m which is the George Vth Basin. The basin coincides with an abrupt transition in seismic character from acoustic basement in the south to seaward (northeasterly) dipping reflectors. On the continental rise, seismic sections were taken across a contourite drift deposit and submarine canyon system in 2500 to 3500 m water depth. Piston cores were collected along the profile of one drift deposit which gave a preliminary Mid-Pliocene age to truncated strata that crop out on the drift's steeper lee side. These data will provide useful site-survey information in support of a proposal sent to the Ocean Drilling Program under the auspices of the SCAR-ANTOSTRAT project for drilling key sites along the Antarctic margin. |
author2 |
HARRIS, PETER TOWNSEND (hasPrincipalInvestigator) HARRIS, PETER TOWNSEND (processor) Geoscience Australia (originator) Australian Antarctic Data Centre (publisher) |
format |
Dataset |
title |
Wilkes Land Glacial History (WEGA) |
title_short |
Wilkes Land Glacial History (WEGA) |
title_full |
Wilkes Land Glacial History (WEGA) |
title_fullStr |
Wilkes Land Glacial History (WEGA) |
title_full_unstemmed |
Wilkes Land Glacial History (WEGA) |
title_sort |
wilkes land glacial history (wega) |
publisher |
Australian Antarctic Data Centre |
url |
https://researchdata.ands.org.au/wilkes-land-glacial-history-wega/699373 https://data.aad.gov.au/metadata/records/ASAC_1044 |
op_coverage |
Spatial: northlimit=-64.0; southlimit=-67.5; westlimit=142.0; eastLimit=146.0; projection=WGS84 Temporal: From 2000-09-30 to 2001-03-31 |
long_lat |
ENVELOPE(144.500,144.500,-67.667,-67.667) ENVELOPE(145.500,145.500,-67.167,-67.167) ENVELOPE(144.000,144.000,-65.250,-65.250) ENVELOPE(120.000,120.000,-69.000,-69.000) ENVELOPE(142.0,146.0,-64.0,-67.5) |
geographic |
Antarctic Mertz Glacier Mertz Glacier Tongue Southern Ocean The Antarctic Wega Wilkes Land |
geographic_facet |
Antarctic Mertz Glacier Mertz Glacier Tongue Southern Ocean The Antarctic Wega Wilkes Land |
genre |
Antarc* Antarctic Mertz Glacier Sea ice Southern Ocean Wilkes Land |
genre_facet |
Antarc* Antarctic Mertz Glacier Sea ice Southern Ocean Wilkes Land |
op_source |
Australian Antarctic Data Centre |
op_relation |
https://researchdata.ands.org.au/wilkes-land-glacial-history-wega/699373 a83de475-cffb-412b-b616-9584e28729dd ASAC_1044 https://data.aad.gov.au/metadata/records/ASAC_1044 |
_version_ |
1766245819135033344 |
spelling |
ftands:oai:ands.org.au::699373 2023-05-15T13:46:57+02:00 Wilkes Land Glacial History (WEGA) HARRIS, PETER TOWNSEND (hasPrincipalInvestigator) HARRIS, PETER TOWNSEND (processor) Geoscience Australia (originator) Australian Antarctic Data Centre (publisher) Spatial: northlimit=-64.0; southlimit=-67.5; westlimit=142.0; eastLimit=146.0; projection=WGS84 Temporal: From 2000-09-30 to 2001-03-31 https://researchdata.ands.org.au/wilkes-land-glacial-history-wega/699373 https://data.aad.gov.au/metadata/records/ASAC_1044 unknown Australian Antarctic Data Centre https://researchdata.ands.org.au/wilkes-land-glacial-history-wega/699373 a83de475-cffb-412b-b616-9584e28729dd ASAC_1044 https://data.aad.gov.au/metadata/records/ASAC_1044 Australian Antarctic Data Centre climatologyMeteorologyAtmosphere elevation geoscientificInformation oceans SEAFLOOR TOPOGRAPHY EARTH SCIENCE BATHYMETRY/SEAFLOOR TOPOGRAPHY WATER DEPTH SEDIMENT TRANSPORT COASTAL PROCESSES SEDIMENTATION CONTINENTAL MARGINS SEDIMENT COMPOSITION MARINE SEDIMENTS STRATIGRAPHIC SEQUENCE TERRIGENOUS SEDIMENTS TURBIDITY OCEAN CURRENTS OCEAN CIRCULATION THERMOHALINE CIRCULATION WATER TEMPERATURE OCEAN TEMPERATURE CONDUCTIVITY SALINITY/DENSITY MICROFOSSILS PALEOCLIMATE OCEAN/LAKE RECORDS PALEOMAGNETIC DATA RADIOCARBON SEDIMENTS SEISMIC PROFILE SOLID EARTH TECTONICS EARTHQUAKES WEGA seismic Cenozoic R/V TANGAROA Paleo Start Date Paleo Stop Date PHANEROZOIC > OCEAN > SOUTHERN OCEAN GEOGRAPHIC REGION > POLAR dataset ftands 2020-01-05T21:16:10Z A collaborative Italian/Australian marine geoscience research voyage to the George Vth Land sector of the East Antarctic continental margin was carried out between 11th February and 20th March, 2000, on board the of the RV Tangaroa. The cost of the expedition was shared jointly by the Italian and Australian National Antarctic Research Programs. Twenty four scientific personnel from 13 institutions participated in the expedition. The geophysical data collected includes a total of 1827 km of multi-channel seismic data and 562 km of Chirper sonar data. A total of 11 gravity cores, 28 piston cores, 18 surface grabs and 11 short trigger cores were collected on the voyage. Water profile (CTD) measurements and water samples were collected at nine stations and seabed bottom photographs were made at 11 stations. The expedition discovered and mapped a shelf sediment drift deposit covering about 400 km2 lying in an greater than 800m deep section of the George Vth basin west of the Mertz Glacier. It is a true 'drift' deposit, since these sediments exhibit a patchy distribution, large-scale bedforms, contain foreset bedding and display a depositional architecture indicative of contour-parallel sediment transport. A significant observation is that the drift thins to the north into an acoustically-transparent veneer; this observation implies that the drift is sourced from the outer continental shelf, with sediment being transported landwards, across the shelf and into an 850m deep inner shelf basin. The 'Mertz Drift' is over 35 m thick and core samples demonstrate that it is composed of laminated, anoxic, gelatinous olive green, silicious mud and diatom ooze (SMO). Preliminary shipboard counts of the laminae suggest a thickness of from 4 to 20mm, with a mean of about 7mm. While the lower sediments are laminated, there is a 20 to 50cm thick sandy drape at the surface over the whole of the drift. This suggests that a recent (late Holocene) change in the depositional environment has occurred, possibly related to changes in the extent of the nearby Mertz Glacier tongue, current regime and/or to the persistence of sea ice over the shelf area. Multi-channel seismic data show the occurrence of foreset beds at the shelf break, interpreted as having been deposited by ice streams that grounded on the outer shelf during glacial maxima. On the shelf, the seismic character of the seafloor exhibits highly reflective, parabolic reflectors suggestive of crystalline basement, cropping out at the seafloor. Northwards of these basement outcrops, the water depth increases to over 1,100 m which is the George Vth Basin. The basin coincides with an abrupt transition in seismic character from acoustic basement in the south to seaward (northeasterly) dipping reflectors. On the continental rise, seismic sections were taken across a contourite drift deposit and submarine canyon system in 2500 to 3500 m water depth. Piston cores were collected along the profile of one drift deposit which gave a preliminary Mid-Pliocene age to truncated strata that crop out on the drift's steeper lee side. These data will provide useful site-survey information in support of a proposal sent to the Ocean Drilling Program under the auspices of the SCAR-ANTOSTRAT project for drilling key sites along the Antarctic margin. Dataset Antarc* Antarctic Mertz Glacier Sea ice Southern Ocean Wilkes Land Research Data Australia (Australian National Data Service - ANDS) Antarctic Mertz Glacier ENVELOPE(144.500,144.500,-67.667,-67.667) Mertz Glacier Tongue ENVELOPE(145.500,145.500,-67.167,-67.167) Southern Ocean The Antarctic Wega ENVELOPE(144.000,144.000,-65.250,-65.250) Wilkes Land ENVELOPE(120.000,120.000,-69.000,-69.000) ENVELOPE(142.0,146.0,-64.0,-67.5) |