The Effects of Glacial Melting on Precipitation Patterns in Jellyfish Lake, Palau Derived from Hydrogen Isotopes in Algal Lipids
A meltwater-induced disruption of the Atlantic Meridional Overturning Circulation (AMOC) 8.5- 8 kyr impacted climate globally, with evidence from around the continental Pacific suggesting large perturbations to rainfall patterns. Modeling indicates a southward shift of the tropical rainbands during...
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ftunivwashington:oai:digital.lib.washington.edu:1773/47764 2023-05-15T17:35:59+02:00 The Effects of Glacial Melting on Precipitation Patterns in Jellyfish Lake, Palau Derived from Hydrogen Isotopes in Algal Lipids Kraft, Alana 2021 http://hdl.handle.net/1773/47764 unknown http://hdl.handle.net/1773/47764 Glacial melting Jellyfish Lake Palau Atlantic Meridional Overturning Circulation Intertropical Convergence Zone 2021 ftunivwashington 2023-03-12T19:01:09Z A meltwater-induced disruption of the Atlantic Meridional Overturning Circulation (AMOC) 8.5- 8 kyr impacted climate globally, with evidence from around the continental Pacific suggesting large perturbations to rainfall patterns. Modeling indicates a southward shift of the tropical rainbands during this time. However, this is largely untested due to a lack of paleoclimate data where the Intertropical Convergence Zone (ITCZ) is well defined. In this project, I analyze hydrogen isotopic data (2H/1H) from well-dated sediment cores taken from Jellyfish Lake, Palau that imply a southward shift of the ITCZ during this time. Due to this lake being a uniquely undisturbed area with a high rate of sediment accumulation, the isotopic composition of dinosterol in these sediments can provide a detailed reconstruction of past rainfall in the tropics. Dinosterol is an organic compound produced exclusively by dinoflagellates, a taxa of photosynthetic microalgae. Through this “molecular fossil,” I can reconstruct the 2H/1H ratio of the lake water and its salinity, both of which are directly tied to rainfall in Palau. To identify and purify the dinosterol found in sediment core samples, I use High-Performance Liquid Chromatography (HPLC), Gas-Chromatography-Mass Spectrometry (GC-MS), and Gas Chromatography-Flame Ionization Detection (GC-FID) instruments. Using Gas Chromatography- Isotope Ratio Mass Spectrometry (GC-IRMS), I found large and systematic fluctuations in the 2H/1H ratios of dinosterol. Thus, the preliminary data demonstrate a trend toward a drier climate in Palau at the time of the glacial meltwater pulse into the North Atlantic 8,200 years ago, consistent with a southward shift of the ITCZ. Over the past century, there has been a substantial increase in glacial melting due to anthropogenically-induced climate change. This paleoclimatic data has important implications in furthering our understanding of how drastic alterations in ocean circulation could affect climate on a global scale. Other/Unknown Material North Atlantic University of Washington, Seattle: ResearchWorks Fid ENVELOPE(-65.939,-65.939,-68.664,-68.664) Pacific |
institution |
Open Polar |
collection |
University of Washington, Seattle: ResearchWorks |
op_collection_id |
ftunivwashington |
language |
unknown |
topic |
Glacial melting Jellyfish Lake Palau Atlantic Meridional Overturning Circulation Intertropical Convergence Zone |
spellingShingle |
Glacial melting Jellyfish Lake Palau Atlantic Meridional Overturning Circulation Intertropical Convergence Zone Kraft, Alana The Effects of Glacial Melting on Precipitation Patterns in Jellyfish Lake, Palau Derived from Hydrogen Isotopes in Algal Lipids |
topic_facet |
Glacial melting Jellyfish Lake Palau Atlantic Meridional Overturning Circulation Intertropical Convergence Zone |
description |
A meltwater-induced disruption of the Atlantic Meridional Overturning Circulation (AMOC) 8.5- 8 kyr impacted climate globally, with evidence from around the continental Pacific suggesting large perturbations to rainfall patterns. Modeling indicates a southward shift of the tropical rainbands during this time. However, this is largely untested due to a lack of paleoclimate data where the Intertropical Convergence Zone (ITCZ) is well defined. In this project, I analyze hydrogen isotopic data (2H/1H) from well-dated sediment cores taken from Jellyfish Lake, Palau that imply a southward shift of the ITCZ during this time. Due to this lake being a uniquely undisturbed area with a high rate of sediment accumulation, the isotopic composition of dinosterol in these sediments can provide a detailed reconstruction of past rainfall in the tropics. Dinosterol is an organic compound produced exclusively by dinoflagellates, a taxa of photosynthetic microalgae. Through this “molecular fossil,” I can reconstruct the 2H/1H ratio of the lake water and its salinity, both of which are directly tied to rainfall in Palau. To identify and purify the dinosterol found in sediment core samples, I use High-Performance Liquid Chromatography (HPLC), Gas-Chromatography-Mass Spectrometry (GC-MS), and Gas Chromatography-Flame Ionization Detection (GC-FID) instruments. Using Gas Chromatography- Isotope Ratio Mass Spectrometry (GC-IRMS), I found large and systematic fluctuations in the 2H/1H ratios of dinosterol. Thus, the preliminary data demonstrate a trend toward a drier climate in Palau at the time of the glacial meltwater pulse into the North Atlantic 8,200 years ago, consistent with a southward shift of the ITCZ. Over the past century, there has been a substantial increase in glacial melting due to anthropogenically-induced climate change. This paleoclimatic data has important implications in furthering our understanding of how drastic alterations in ocean circulation could affect climate on a global scale. |
author |
Kraft, Alana |
author_facet |
Kraft, Alana |
author_sort |
Kraft, Alana |
title |
The Effects of Glacial Melting on Precipitation Patterns in Jellyfish Lake, Palau Derived from Hydrogen Isotopes in Algal Lipids |
title_short |
The Effects of Glacial Melting on Precipitation Patterns in Jellyfish Lake, Palau Derived from Hydrogen Isotopes in Algal Lipids |
title_full |
The Effects of Glacial Melting on Precipitation Patterns in Jellyfish Lake, Palau Derived from Hydrogen Isotopes in Algal Lipids |
title_fullStr |
The Effects of Glacial Melting on Precipitation Patterns in Jellyfish Lake, Palau Derived from Hydrogen Isotopes in Algal Lipids |
title_full_unstemmed |
The Effects of Glacial Melting on Precipitation Patterns in Jellyfish Lake, Palau Derived from Hydrogen Isotopes in Algal Lipids |
title_sort |
effects of glacial melting on precipitation patterns in jellyfish lake, palau derived from hydrogen isotopes in algal lipids |
publishDate |
2021 |
url |
http://hdl.handle.net/1773/47764 |
long_lat |
ENVELOPE(-65.939,-65.939,-68.664,-68.664) |
geographic |
Fid Pacific |
geographic_facet |
Fid Pacific |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://hdl.handle.net/1773/47764 |
_version_ |
1766135313459052544 |