Overview
Background
The focus of my research is on the oceanography and paleoceanography. I use stable isotopes (oxygen, carbon), geochemical tracers, sedimentology and microfossils to understand the present and past changes in ocean chemistry to reconstruct ocean circulation (changes in ocean currents and fronts) and its relationship to global climate. I am particularly interested in understanding past changes in the Great Barrier Reef, and at the other extreme past changes in processe at the Antarctic Margin. I am also interested in mapping marine sediment distribution, sediment transport processes, marine geomorphology, and multidisciplinary topics such as ocean acidification (the uptake of CO2 by the oceans) and climate change in the oceans (marine heat waves, sea level rise), and paleoseismicity (using sedimentary records to reconstruct the history of past earthquakes). My research has focussed on the southwest Pacific (Coral Sea, Tasman Sea and South Pacific) and Southern Ocean. I have participated in a number of research voyages on open ocean vessels including the RV Tangaroa and RV Investigator, including several as lead or co-lead scientist.
Helen Bostock joined the University of Queensland in July 2019 from the National Institute of Water and Atmospheric Research in New Zealand (2006-2019). Prior to this she worked as a researcher in the Coastal CRC at Geoscience Australia in Canberra (2004-2006).
Availability
- Associate Professor Helen Bostock Lyman is:
- Available for supervision
- Media expert
Fields of research
Qualifications
- Doctor of Philosophy, Australian National University
Research interests
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Past changes in the Southern Ocean
I am interested in past changes in ocean circulation in the Southern Ocean over glacial/interglacial timescales (1000s-100,000s years). I use proxy evidence from sedimentary characteristics, microfossil assemblages, stable isotopes (carbon, oxygen, nitrogen and boron), elemental variations from a latitudinal transect of marine sediment cores from the subtropical waters of the southwest Pacific to the continental margin of Antarctica. I try to reconstruct changes in temperature, biological productivity, changes in water masses, ocean currents and fronts, sea ice, ice sheet retreat, and how all these different processes are linked to global climate.
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Geological history of the Great Barrier Reef
I am interested in the initiation and development of the Great Barrier Reef using proxies (sedimentology, microfossil assemblages, stable isotopes, geochemistry) from marine sediment cores offshore. The aim is to understand the timing of the reef development, but also to understand the broader regional ocean circulation of the Coral Sea over glacial/interglacial timescales (1000s-100,000s-1,000,000 years).
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The carbon cycle in the ocean and ocean acidification
I look at the geochemistry of the water column, primarily the carbonate chemistry and carbon isotopes, to understand changes in the ocean carbon cycle over recent decades due to the uptake of anthropogenic CO2 from the atmosphere. This results in a decline in the pH in the ocean, a process known as ocean acidification. I also work with collaborators using Boron isotopes of microfossils in marine sediment cores to understand how pH and carbonate concentrations have changed over glacial/interglacial timescales.
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Sedimentary processes in the ocean
I look at the distribution of sediment in the marine environment from coastal to the deep ocean. The sediment type is dependent on the local source from nearby rivers, as well as biological productivity (e.g. shells and skeletons) and authigenic sediment (geochemically precipitated out of the seawater). Sediment is redistributed by gravity and ocean currents. The distribution of sediment in the marine environment is important to determine marine benthic (seafloor) habitats. The recurrence of gravity transported sediment (called turbidites or debrites) along tectonically active continental margins has been used to study the frequency of large earthquakes.
Research impacts
The work undertaken as part of the Coastal CRC (https://ozcoasts.org.au/) looked at several different coastal enviroments around Australia to understand the impact of recent sediment and contaminants on the local ecosystems, such as the Great Barrier Reef.
I have developed datasets of the carbonate chemistry and sediment maps of the southwest Pacific, which have been widely used by marine ecologists to understand the habitats of marine organisms that live on the seafloor. These datasets have been used to identify the potential distribution of deep marine vulnerable marine ecosystems in the South Pacific. I have also been involved in a New Zealand project CARIM (Coastal Acidification: Rates, Impacts and Mitigation) to determine the variability of pH and carbonate chemistry of the coastal regions. These projects have Maori and regional government stakeholders that will be using this information to develop future strategic management plans.
I have also been involved in a large project to understand recurrence of large earthquakes on the Hikurangi Subduction Margin, east coast of the New Zealand north island. This project is using a suite of cores from across the margin to look at the frequency of sedimentary gravity flows (turbidites), to determine the occurrence of earthquakes along this margin to develop hazard models for the east coast of the North Island communities and New Zealand government.
Works
Search Professor Helen Bostock Lyman’s works on UQ eSpace
2007
Journal Article
Holocene and modern sediment storage in the subtropical macrotidal Fitzroy River estuary, Southeast Queensland, Australia
Bostock, Helen C., Brooke, Brendan P., Ryan, David A., Hancock, Gary, Pietsch, Tim, Packett, Robert and Harle, Kate (2007). Holocene and modern sediment storage in the subtropical macrotidal Fitzroy River estuary, Southeast Queensland, Australia. Sedimentary Geology, 201 (3-4), 321-340. doi: 10.1016/j.sedgeo.2007.07.001
2007
Journal Article
Bathymetric expression of the Fitzroy River palaeochannel, northeast Australia: Response of a major river to sea-level change on a semi-rimmed, mixed siliciclastic-carbonate shelf
Ryan, David A., Bostock, Helen C., Brooke, Brendan P. and Marshall, John F. (2007). Bathymetric expression of the Fitzroy River palaeochannel, northeast Australia: Response of a major river to sea-level change on a semi-rimmed, mixed siliciclastic-carbonate shelf. Sedimentary Geology, 201 (1-2), 196-211. doi: 10.1016/j.sedgeo.2007.05.018
2007
Journal Article
Bedload sediment transport dynamics in a macrotidal embayment, and implications for export to the southern Great Barrier Reef shelf
Ryan, David A., Brooke, Brendan P., Bostock, Helen C., Radke, Lynda C., Siwabessy, Paulus J. W., Margvelashvili, Nugzar and Skene, Darren (2007). Bedload sediment transport dynamics in a macrotidal embayment, and implications for export to the southern Great Barrier Reef shelf. Marine Geology, 240 (1-4), 197-215. doi: 10.1016/j.margeo.2007.02.014
2006
Journal Article
Glacial/interglacial changes in the East Australian current
Bostock, H. C., Opdyke, B. N., Gagan, M. K., Kiss, A. E. and Fifield, L. K. (2006). Glacial/interglacial changes in the East Australian current. Climate Dynamics, 26 (6), 645-659. doi: 10.1007/s00382-005-0103-7
2006
Conference Publication
Mg/Ca, stable isotopes and an important paleo-salintiy record from the indo-pacific warm pool
Opdyke, B. N., Edwards, J., Bostock, H. C., Lea, D. W., Spero, H. J., Gagan, M. and Fifield, K. (2006). Mg/Ca, stable isotopes and an important paleo-salintiy record from the indo-pacific warm pool. 16th Annual V M Goldschmidt Conference, Melbourne, VIC Australia, 27 August - 1 September 2006. Oxford, United Kingdom: Elsevier. doi: 10.1016/j.gca.2006.06.926
2005
Journal Article
Preliminary results on Cretaceous-Tertiary tropical Atlantic pelagic sedimentation (Demerara Rise, ODP Leg 207) Résultats préliminaires sur la sédimentation pélagique de l'Atlantique tropical au Crétacé et au Tertiaire (plateau de Demerara, Leg ODP 207)
Danelian, Taniel, Le Callonnec, Laurence, Erbacher, Jochen, Mosher, David C., Malone, Mitchell J., Berti, Debora, Bice, Karen L., Bostock, Helen, Brumsack, Hans-Jürgen, Forster, Astrid, Heidersdorf, Felix, Henderiks, Jorijntje, Janecek, Thomas J., Junium, Christopher, MacLeod, Ken, Meyers, Philip A., Mutterlose, Jörg H., Nishi, Hiroshi, Norris, Richard D., Ogg, James G., O'Regan, Matthew A., Rea, Brice, Sexton, Philip, Sturt-Fredricks, Helen, Suganuma, Yusuke, Thurow, Jürgen W., Wilson, Paul A., Wise, Sherwood W. and Glatz, Christine (2005). Preliminary results on Cretaceous-Tertiary tropical Atlantic pelagic sedimentation (Demerara Rise, ODP Leg 207) Résultats préliminaires sur la sédimentation pélagique de l'Atlantique tropical au Crétacé et au Tertiaire (plateau de Demerara, Leg ODP 207). Comptes Rendus - Geoscience, 337 (6), 609-616. doi: 10.1016/j.crte.2005.01.011
2004
Journal Article
Carbon isotope evidence for changes in Antarctic Intermediate Water circulation and ocean ventilation in the southwest Pacific during the last deglaciation
Bostock, Helen C., Opdyke, Bradley N., Gagan, Michael K. and Fifield, L. Keith (2004). Carbon isotope evidence for changes in Antarctic Intermediate Water circulation and ocean ventilation in the southwest Pacific during the last deglaciation. Paleoceanography, 19 (4), n/a-n/a. doi: 10.1029/2004PA001047
Supervision
Availability
- Associate Professor Helen Bostock Lyman is:
- Available for supervision
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Available projects
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Microplastics in Moreton Bay
Globally we consume and dispose of significant quanitites of plastic. Some of these end up in our water ways and eventually make it to the coast and out into the ocean. This project will look at the distribution, concentration of microplastics in Moreton Bay, Southeast Queensland sediments and waters to determine how much microplastic is getting in to and being trapped in this coastal embayment.
The student should have an interest in environmental and marine sciences. The project will involve field work, lab work and with the potential for some modelling. The project is joint with the Queensland Alliance for Environmental Health Science at UQ and Engineering School.
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Oceanography and Paleoceanography of the Coral Sea
The Coral Sea sits offshore northeast Queensland, Australia, and has a strong influence on the Great Barrier Reef and other reefs within the large Coral Sea Marine Park. However, we still have little understanding of the oceanography and paleoceanography of this region and how it has evolved and influenced the development of the reef over the last 1 million years.
The project will involve analysing oceanographic data from the region, and also lab work to process some recently collected long marine sediment cores from the northern Great Barrier Reef (2022) for their microfossils, sedimentology and stable isotopes.
This project would require someone with an oceanographic and/or a marine geology/sedimentology/geochemistry background.
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Changes in the Antarctic Intermediate Water around Australia over the last glacial cycle
Antarctic Intermediate Water (AAIW) sits at a water depth of 500-1500 m around Australia. This water mass that forms in the Southern Ocean plays an important role in the uptake of carbon and is thought to play an important role in providing nutrients to the subtropics. The AAIW has also been proposed to play an key role in the climate change over glacial cycles. Despite this we know relatively little about this water mass around Australia and how it has changed over time and its influence on the regional climate.
This project will look at oceanographic data and process a series of marine sediment cores from the Indian, Southern and Pacific oceans to understand past changes in AAIW over the last glacial cycle (~150 ka). The project will involve lab work to process microfossils and stable isotopes and other geochemical proxies.
The project would suit someone with an oceanography and/or marine geology/sedimentology/micropaleontology background.
Supervision history
Current supervision
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Doctor Philosophy
Exploring the interactions of the East Australian Current with canyons
Principal Advisor
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Doctor Philosophy
Reconstructing past environmental changes in the Cape Darnley, East Antarctica, region using microfossils from marine sediment cores
Principal Advisor
Other advisors: Dr Kevin Welsh
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Doctor Philosophy
Oceanography and modelling on the Cape Darnley region, East Antarctica
Principal Advisor
Completed supervision
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2023
Doctor Philosophy
New radiolarian-based methods for estimating water mass and sea-ice changes in the Southwest Pacific Sector of the Southern Ocean
Principal Advisor
Other advisors: Professor Jonathan Aitchison, Dr Jason Everett
Media
Enquiries
Contact Associate Professor Helen Bostock Lyman directly for media enquiries about:
- Ocean carbon
- Oceanography
- Past climate
- Seafloor mapping
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