Carbon isotopic equilibrium of the surface waters as a proxy for climate change through the last glacial/interglacial cycle in the Southwest Pacific
Carbon-13 is a relatively understudied geochemical property in the world ocean. The Southwest Pacific, in particular, is devoid of δ¹³C data. This thesis therefore has two main objectives: to create a model to describe the modern distribution of δ¹³C around New Zealand (30-70°S, 140°E-150°W), and to...
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ftsmithonian:oai:figshare.com:article/17060372 2023-05-15T14:03:39+02:00 Carbon isotopic equilibrium of the surface waters as a proxy for climate change through the last glacial/interglacial cycle in the Southwest Pacific Maxson IV, Charles Reynolds (11738042) 2017-01-01T00:00:00Z https://doi.org/10.26686/wgtn.17060372.v1 unknown https://figshare.com/articles/thesis/Carbon_isotopic_equilibrium_of_the_surface_waters_as_a_proxy_for_climate_change_through_the_last_glacial_interglacial_cycle_in_the_Southwest_Pacific/17060372 doi:10.26686/wgtn.17060372.v1 Author Retains Copyright Isotope Geochemistry Carbon Climate change ¹³C School: School of Geography Environment and Earth Sciences 040203 Isotope Geochemistry 970104 Expanding Knowledge in the Earth Sciences Degree Discipline: Geology Degree Level: Masters Degree Name: Master of Science Text Thesis 2017 ftsmithonian https://doi.org/10.26686/wgtn.17060372.v1 2021-12-19T21:04:12Z Carbon-13 is a relatively understudied geochemical property in the world ocean. The Southwest Pacific, in particular, is devoid of δ¹³C data. This thesis therefore has two main objectives: to create a model to describe the modern distribution of δ¹³C around New Zealand (30-70°S, 140°E-150°W), and to describe changes in δ¹³C in a latitudinal transect of cores to the east and south of New Zealand. A model using multiple linear regression was created by comparing δ¹³C with potential temperature, salinity, density, and oxygen data. This model matches well with ship board δ¹³C measurements taken throughout the region. The resulting models were then compared to core top data to determine how well modern δ¹³C values compare to the Holocene, pre-industrial values. A new model, based on previous pre-industrial models, was created at much higher resolution to recreate the pre-industrial δ¹³C distribution. Core top values were found to be intermediate between Holocene and modern values. Down core δ¹³C data was split into six regions based on oceanographic conditions to determine what caused and how δ¹³C change occurred in the past. Data was run through 1000 iterations of a Monte Carlo simulation to determine a robust δ¹³C curve back through time. The biologic pump was found to dominate the δ¹³C levels in the region through iron fertilization and increased productivity in the polar zone. The LGM and deglacial δ¹³C values reflect greater influence on δ¹³Catm, suggesting that an increase in upwelling along the Antarctic coast and a possible strengthening of the westerly wind belt caused changes in ocean circulation throughout the region. The ACR and Early Holocene periods show good correlation with atmospheric CO₂ records, suggesting increasing temperatures may have increased productivity. The remainder of the Holocene to the present is mainly influenced by δ¹³Catm, suggesting relatively stable conditions in ocean and atmosphere. Thesis Antarc* Antarctic Unknown Antarctic New Zealand Pacific The Antarctic |
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Open Polar |
collection |
Unknown |
op_collection_id |
ftsmithonian |
language |
unknown |
topic |
Isotope Geochemistry Carbon Climate change ¹³C School: School of Geography Environment and Earth Sciences 040203 Isotope Geochemistry 970104 Expanding Knowledge in the Earth Sciences Degree Discipline: Geology Degree Level: Masters Degree Name: Master of Science |
spellingShingle |
Isotope Geochemistry Carbon Climate change ¹³C School: School of Geography Environment and Earth Sciences 040203 Isotope Geochemistry 970104 Expanding Knowledge in the Earth Sciences Degree Discipline: Geology Degree Level: Masters Degree Name: Master of Science Maxson IV, Charles Reynolds (11738042) Carbon isotopic equilibrium of the surface waters as a proxy for climate change through the last glacial/interglacial cycle in the Southwest Pacific |
topic_facet |
Isotope Geochemistry Carbon Climate change ¹³C School: School of Geography Environment and Earth Sciences 040203 Isotope Geochemistry 970104 Expanding Knowledge in the Earth Sciences Degree Discipline: Geology Degree Level: Masters Degree Name: Master of Science |
description |
Carbon-13 is a relatively understudied geochemical property in the world ocean. The Southwest Pacific, in particular, is devoid of δ¹³C data. This thesis therefore has two main objectives: to create a model to describe the modern distribution of δ¹³C around New Zealand (30-70°S, 140°E-150°W), and to describe changes in δ¹³C in a latitudinal transect of cores to the east and south of New Zealand. A model using multiple linear regression was created by comparing δ¹³C with potential temperature, salinity, density, and oxygen data. This model matches well with ship board δ¹³C measurements taken throughout the region. The resulting models were then compared to core top data to determine how well modern δ¹³C values compare to the Holocene, pre-industrial values. A new model, based on previous pre-industrial models, was created at much higher resolution to recreate the pre-industrial δ¹³C distribution. Core top values were found to be intermediate between Holocene and modern values. Down core δ¹³C data was split into six regions based on oceanographic conditions to determine what caused and how δ¹³C change occurred in the past. Data was run through 1000 iterations of a Monte Carlo simulation to determine a robust δ¹³C curve back through time. The biologic pump was found to dominate the δ¹³C levels in the region through iron fertilization and increased productivity in the polar zone. The LGM and deglacial δ¹³C values reflect greater influence on δ¹³Catm, suggesting that an increase in upwelling along the Antarctic coast and a possible strengthening of the westerly wind belt caused changes in ocean circulation throughout the region. The ACR and Early Holocene periods show good correlation with atmospheric CO₂ records, suggesting increasing temperatures may have increased productivity. The remainder of the Holocene to the present is mainly influenced by δ¹³Catm, suggesting relatively stable conditions in ocean and atmosphere. |
format |
Thesis |
author |
Maxson IV, Charles Reynolds (11738042) |
author_facet |
Maxson IV, Charles Reynolds (11738042) |
author_sort |
Maxson IV, Charles Reynolds (11738042) |
title |
Carbon isotopic equilibrium of the surface waters as a proxy for climate change through the last glacial/interglacial cycle in the Southwest Pacific |
title_short |
Carbon isotopic equilibrium of the surface waters as a proxy for climate change through the last glacial/interglacial cycle in the Southwest Pacific |
title_full |
Carbon isotopic equilibrium of the surface waters as a proxy for climate change through the last glacial/interglacial cycle in the Southwest Pacific |
title_fullStr |
Carbon isotopic equilibrium of the surface waters as a proxy for climate change through the last glacial/interglacial cycle in the Southwest Pacific |
title_full_unstemmed |
Carbon isotopic equilibrium of the surface waters as a proxy for climate change through the last glacial/interglacial cycle in the Southwest Pacific |
title_sort |
carbon isotopic equilibrium of the surface waters as a proxy for climate change through the last glacial/interglacial cycle in the southwest pacific |
publishDate |
2017 |
url |
https://doi.org/10.26686/wgtn.17060372.v1 |
geographic |
Antarctic New Zealand Pacific The Antarctic |
geographic_facet |
Antarctic New Zealand Pacific The Antarctic |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_relation |
https://figshare.com/articles/thesis/Carbon_isotopic_equilibrium_of_the_surface_waters_as_a_proxy_for_climate_change_through_the_last_glacial_interglacial_cycle_in_the_Southwest_Pacific/17060372 doi:10.26686/wgtn.17060372.v1 |
op_rights |
Author Retains Copyright |
op_doi |
https://doi.org/10.26686/wgtn.17060372.v1 |
_version_ |
1766274438048776192 |