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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Main Author: Maxson IV, Charles Reynolds
Format: Thesis
Language:unknown
Published: 2017
Subjects:
Online Access:https://doi.org/10.26686/wgtn.17060372.v1
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
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spelling ftvictoriauwfig:oai:figshare.com:article/17060372 2023-05-15T13:35:14+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 2017-01-01T00:00:00Z https://doi.org/10.26686/wgtn.17060372.v1 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 unknown doi:10.26686/wgtn.17060372.v1 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 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 ftvictoriauwfig https://doi.org/10.26686/wgtn.17060372.v1 2021-11-25T00:04:10Z 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 Open Access Victoria University of Wellington / Te Herenga Waka Antarctic The Antarctic Pacific New Zealand
institution Open Polar
collection Open Access Victoria University of Wellington / Te Herenga Waka
op_collection_id ftvictoriauwfig
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
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
author_facet Maxson IV, Charles Reynolds
author_sort Maxson IV, Charles Reynolds
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
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
geographic Antarctic
The Antarctic
Pacific
New Zealand
geographic_facet Antarctic
The Antarctic
Pacific
New Zealand
genre Antarc*
Antarctic
genre_facet Antarc*
Antarctic
op_relation doi:10.26686/wgtn.17060372.v1
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
op_rights Author Retains Copyright
op_doi https://doi.org/10.26686/wgtn.17060372.v1
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