Fully Funded PhD Scholarship in Palaeoceanography Geography - Tenders Global

Fully Funded PhD Scholarship in Palaeoceanography Geography

National University of Ireland Galway (NUI Galway)

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National University of Ireland Galway (NUI Galway)

Fully Funded PhD Scholarship in Palaeoceanography
Geography, iCRAG SFI Research Centre

Application(s) are invited from suitably qualified candidates for full-time funded PhD
scholarship(s) starting in March, 2023 affiliated to the College of Arts/School of Geography,
Archaeology and Irish Studies/Geography/iCRAG at the University of Galway.

University of Galway:
Located in the vibrant cultural city of Galway in the west of Ireland, with over 18,000 students
and more than 2,400 staff, the University of Galway has a distinguished reputation for
teaching and research excellence https://www.universityofgalway.ie/our-research/

The successful candidate(s) will undertake training and research on
PhD 1: The impact of physiological and ontogenetic processes on geochemical tracers
recorded in planktonic foraminifera.

PhD 2: The impact of early diagenetic processes in surface marine sediments on geochemical
tracers recorded in planktonic foraminifera

Brief Project Description
Project SiTrAc pioneers a novel cross disciplinary approach to develop and apply indirect
measures of climate to assess past Arctic climate variability and its sensitivity to climate
forcing. These will provide the critical basis to resolve existing debates on the stability of our
climate system.

Detailed Project Description
Arctic climate change has global implications because some of the most sensitive tipping
points amplifying global variability (such as deep-water formation, sea ice extent, thawing
permafrost) are intrinsic to the Arctic region. Nonetheless, our understanding of climate
tipping points and their impact on future Arctic and global climate remains limited due to the
shortness of observational records and the absence of prominent, high-impact events to
serve as potential analogues for future change. It is essential therefore to develop and apply
indirect measures of climate to assess past Arctic climatic variability, stability, and sensitivity
to climate forcing. To date, the majority of climate proxies are unable to quantify sea surface
temperatures or the carbonate system in Arctic/Subarctic Oceans because biological and
physiochemical processes besides temperature influence their geochemical composition in
cold seawater. SiTrAc addresses this critical gap by pioneering a new holistic multidisciplinary
approach to palaeoceanographic proxy development that considers foraminifera as a living
organism and not just as a proxy carrier. Using innovative biogeochemical techniques and
micro-structural analyses of polar foraminifera Neogloboquadrina pachyderma (NP), which is
the dominant and often only species present in surface waters below 4C, SiTrAc will track
essential climate variables via the living proxy into the archive (i.e., marine sediments).
Further, SiTrAc’s unique research strategy will quantify the biological and physiochemical processes influencing how geochemical tracers are recorded at the time of proxy
development, thereby advancing our understanding both of proxies and Arctic climate. SiTrAc
forms the critical basis for testing new hypotheses for the drivers and tipping points of Arctic
and global change past, present, and future.

PhD 1: The impact of physiological and ontogenetic processes on geochemical tracers recorded in planktonic foraminifera
The leading hypotheses describing the incorporation of Mg, B, O, and C species into calcium
carbonate proposes that alongside seawater pH/carbonate ion and temperature, calcification
and metabolic rates exert a control on the geochemical composition and isotopic
fractionation in planktonic foraminifera (PF). Also, it is often assumed that PF migrate
vertically in the water column during their life cycle. However, whether this is the case and
how/if migration influences the geochemical tracer recorded in pristine calcite, and how it is
subsequently represented in climate archives remains unknown. To address these gaps in
knowledge it is therefore essential to determine the impact of both physiological and
ontogenetic processes on geochemical tracers recorded in live PF.

To achieve these goals, the successful candidate will constrain PF respiration/metabolic rates
on living specimen collected via plankton tows from Greenland, Irminger, and Labrador Seas
to empirically constrain the hypothesised relationship between porosity and respiration for
PF. Further, the candidate will determine calcification and growth rates of the same
individuals using 3D volume reconstructions of test chambers using novel advances in
microCT imaging to identify individual chamber thickness and volume during growth. The
successful candidate will also constrain the hydrographic parameters of the calcification
environment to identify the empirical relationships between geochemical tracers, essential
climate variables, respiration, calcification, and growth rates. To assess vertical migration, live
PF specimen will be collected and analysed from closely spaced tows (e.g., 20 m depth
intervals). These will elucidate whether geochemical signals can be traced to distinct depth
intervals and thereby constrain migration. This PhD position will be Co-supervised by Dr
Audrey Morley (University of Galway) and Dr Julie Meilland (MARUM, Bremen University).

PhD 2: The impact of early diagenetic processes in surface marine sediments on geochemical tracers recorded in planktonic foraminifera
Early diagenetic processes begin the moment PF touch the sediment. The physical evidence
left behind by early diagenesis in the top-most sediments is expected to be less and not on
the same scales as observed by net dissolution and overgrowth precipitation typically
associated with deep-time diagenesis. Still, recent evidence suggests that early diagenesis
may alter the SST signal of the Mg/Ca – temperature proxy by 2-3 °C. However, the impact of
early dissolution, linked to organic matter degradation and stable mineral recrystallization
(e.g., mineral-fluid exchange) in surface sediments specifically on high Mg phases in PF calcite
are rarely considered or quantified.

To assess early diagenesis of PF at the sea floor, the analysis of pore water geochemistry will
be paired with trace element, isotope, and microstructural analysis (microCT) on recently
deposited NP from a large collection of multicores retrieved from different depositional
environments (e.g., open ocean, slope, shelf). Specifically, the successful candidate will target
the potential of short-term mineral-fluid exchanges within the top 30 cm of sediment, which
exhibits sharp gradients in oxygen, microbial activity, pH, alkalinity, and biological activity for
a diverse set of depositional environments. The impact of recrystallisation on geochemical
tracers will be assessed via paired SEMEDS elemental mapping and solution analysis of Mg,
Sr, Mn, and δ13C. To test if early diagenetic processes are indeed a feature of distinct
depositional environments and porewater chemistries, the successful candidate will also
assess the presence of microstructural and geochemical diagenesis markers in the epibenthic
foraminifera Cibicidoides wuellerstorfi. This will confirm whether observed markers are truly
linked to depositional environments and their respective geochemistry. This PhD position will
be supervised by Dr Audrey Morley (University of Galway).

Living allowance (Stipend): €18,500 per annum, [tax-exempt scholarship award]
University fees: €5,500
Start date: March 1st 2023

Academic Entry Requirements:
Essential Criteria

• Undergraduate and/or Post-graduate thesis in Micropaleontology,
Palaeoceanography, Paleoclimatology, or related fields.
• Academic Excellence
• Proficiency in written and spoken English.
• Must be highly motivated
• The ability to work independently as well as in interdisciplinary research groups.

Desirable Criteria
• Previous laboratory experience using a dissecting microscope
• Comfortable using command driven software programmes (R, Matlab, etc.)
• Should have a suitable background in Micropaleontology Paleoclimatology or
Palaeoceanography, preferably involving marine calcifying organisms / microfossils.

To Apply for the Scholarship:
• CV (two pages max.)
• Cover letter (two pages max.) – Here the applicant is required to describe their interest
in the programme and how their skills/competencies match their selected PhD topic
• Two referees

Please email all documents as one pdf file to [email protected]

Contact Name: Dr Audrey Morley

Contact Email: [email protected]

Application Deadline: 15/01/2023 and time [18:00] (Irish time 24hr format)

For information on moving to Ireland please see www.euraxess.ie

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