2015: Year in review

The Palaeoenvironments group was formed in 2017, as a merger between a number of subgroups. Below are the 2015 Year in Review summaries for the research groups:

Ocean and Climate Change

The Ocean & Climate Change group researches a variety of ocean and climate change topics over different timescales, but mostly over the past 1 million years, using marine sediment cores. We perform an array of analyses in wide-ranging collaborations both within ANU and outside, with a strong international outlook. We routinely include probabilistic statistical analyses and quantitative assessments in our analyses results and interpretations. We collaborate with experts in Earth System, ice-sheet, and Glacio-Isostatic Adjustment modelling, and in geochronology and archaeology. Critical topics concern sea-level change, climate sensitivity, monsoon changes, impacts on biogeochemical cycles (especially the carbon cycle), and the processes behind organic-rich sediment deposition.

In 2015 the group comprised Prof Eelco Rohling, Drs Katharine Grant, Gianluca Marino and Laura Rodriguez-Sanz, and PhD students Jess Amies, Alan Brenner and Rose Manceau. We also hosted visitors from Southampton (UK) for a couple of months each: Dr Fiona Hibbert and PhD candidate Felicity Williams. Dr Hibbert will be joining us as a Postdoctoral Fellow in February 2016.

Drs Gianluca Marino and Katharine Grant operating the core-scanner.

During 2015 we achieved twelve publications, including four in Nature and Nature Communications. Several sampling and exchange visits were undertaken, among which were trips to Kochi (Japan), Bremen (Germany), Southampton (UK), and NIOZ and Utrecht (The Netherlands). We presented posters and talks at the major EGU (Vienna, Austria) and AGU (San Francisco, USA) geoscience conferences, as well as various smaller meetings and workshops that ranged in scope from studies of sea-level to climate-archaeology interactions. Also, we were well represented in both the lecturing and the student attendance at the Urbino Summer School of Paleoclimatology (Italy).

In addition, a new long-term collaboration was followed up through an exchange visit with ETH, Zurich (Switzerland).

Finally, we have installed and started to operate an AVAATECH XRF core-scanner.

 

Paleo and Environmental Magnetism

New Research Projects

Prof. Andrew Roberts was awarded funding for the 3 year ARC Discovery Project: Unmixing First-Order Reversal Curve (FORC) diagrams for quantitative environmental analysis.

International Visitors & Collaborators

  • Assoc. Prof. Greig Paterson, Chinese Academy of Sciences, investigating sediment grain size unmixing.
  • Prof Qingsong Liu, Chinese Academy of Sciences, working on environmental magnetism of sediments.
  • Dr Zhaoxia Jiang, Chinese Academy of Sciences, working on the magnetic properties of hematite and goethite.
  • Dr Ping Liu, Chinese Academy of Sciences, working on microtektites in marine sediments.
  • Dr Adrian Muxworthy, Imperial College London, collaborating on the unmixing of First-Order Reversal Curve Diagrams.
  • Dr Richard Harrison, University of Cambridge, collaborating on the unmixing of First-Order Reversal Curve Diagrams.

New Group Members

Dr Pengxiang Hu, working on the ARC-funded project: How do sediments become magnetised? Construction of an empirical-numerical framework.

Dr Liang Chen, supported by the China Scholarship Council to work on the palaeomagnetism of marine sediments and quantifying the long-term morphology of Earth’s magnetic field.

Invited Conference Presentations

A. P. Roberts, D. Heslop & L. Chang, How do sediments get magnetized? LatinMag 2015, São Paulo, Brazil.

A. P. Roberts, D. Heslop, L. Chang & T. Ouyang, Relative efficiencies of remanence acquisition in biogenic and detrital magnetite. American Geophysical Union Fall Meeting, 2015, San Francisco, USA.

2015 Research Highlight

Figure 1: (a) FORC distribution measured using our new “irregular grid” protocol, which automatically takes more measurements in the regions of a FORC distribution that contain diagnostic features. (b) The traditional “regular grid” protocol employs equally spaced measurements, meaning fewer data points are in the diagnostic regions of the distribution (e.g. a lower usage rate).

In recent years the Paleo & Environmental Magnetism workgroup has dedicated a lot of time to the measurement and interpretation of First-Order Reversal Curve (FORC) diagrams. High-resolution FORC diagrams are now being increasingly used in rock and environmental magnetism, including for detection of biomagnetic signals in sediments. Resolution can be a major barrier to obtaining high-quality FORC diagrams, and time-consuming measurements are necessary to resolve the finest features of a FORC distribution. This year we developed a new experimental protocol that allows different parts of a FORC diagram to be represented at different resolutions through the use of an irregular measurement grid (Figure 1). The field steps used in the irregular measurement grid are determined through measurement of a major hysteresis loop, there our technique is completely objective. By employing an irregular grid, larger numbers of measurements can be made in key regions of a FORC distribution to resolve diagnostic features at higher resolution. This work has been published in the paper Zhao, X., D. Heslop, and A. P. Roberts (2015), A protocol for variable-resolution first-order reversal curve measurements, Geochemistry, Geophysics, Geosystems, 16, 1364–1377.

 

Past Climates and Environmental Impacts

Overview

2015 was another exciting and productive year for the Past Climates & Environmental Impacts group. Our research aims to answer fundamental questions about past climate change and environmental impacts, particularly in the Southern Hemisphere and tropical Australasia. Group members are prominent in the use of geochemical tracers in corals, cave formations, and ice cores to reconstruct temperature, precipitation and vegetation dynamics, and natural hazards such as volcanic eruptions and great earthquakes. While our over-arching goal is to produce new knowledge about Earth’s environment, our findings provide the scientific basis required for successful adaption to society’s most challenging environmental threats, including anthropogenic climate change.

Members 

Group members in the Earth Environment Stable Isotope Laboratory. Front (L to R): Bronwyn Dixon, Mike Gagan, Claire Krause, Ali Kimbrough, Nick Scroxton. Back (L to R): Joan Cowley, Heather Scott-Gagan, Bob Burne, Joe Cali, Nerilie Abram. Photo: Joe Cali.

The group comprises Mike Gagan, Nerilie Abram (ARC QEII Fellow), Bradley Opdyke, their students, and contributions from numerous colleagues. Dr Gagan’s long-term research program in Indonesia with Prof. Wahyoe Hantoro and Dr Danny Natawidjaja (Indonesian Institute of Sciences) currently provides world-class opportunities for a cohort of five PhD scholars. Nick Scroxton (now at the University of Massachusetts) was awarded his PhD on Late Pleistocene environmental impacts on Flores, where Homo floresiensis (the Hobbit) was discovered in 2003. Claire Krause submitted her dissertation on the history of the Australasian monsoon over the last 40,000 years, and has landed a position at Geoscience Australia to start in January 2016, after completing an ARC and NCI-supported postdoctoral project on the Southern Annular Mode with Dr Abram. ARC Discovery grant funding supports PhD candidates Ali Kimbrough (speleothems in Sulawesi) and Jennifer Wurtzel (speleothems in Sumatra), and we welcomed Bethany Ellis (ex. UNSW) who will work on Sunda Strait coral records of the Indian Ocean Dipole.  

Bob Burne is pursuing an M.Phil. on organomineralisation in microbialites in the Yalgorup Lakes, Western Australia. Honours student Cornell Hanxomphou was awarded a First Class mark for his use of speleothems to characterise the different drivers of Tasmanian climate over the last two millennia. ANU Summer Scholars Ben Nistor (Otago) and Sebastian Wong (Newcastle) joined us late in 2015 for several weeks as research interns.  Much of our success is due to the Group’s outstanding Professional Officers, Joe Cali, Joan Cowley and Heather Scott-Gagan, whose dedication and technical capabilities in the Earth Environment Stable Isotope Laboratory make it all possible.

We congratulate Nerilie Abram on earning a continuing appointment at RSES in April following completion of the school’s academic renewal process.

Awards and Honours 

Claire Krause (2nd from left) receives the Robert Hill Memorial Prize at her presentation of the Hill Memorial seminar on 25 November 2015. Also shown are fellow PhD students Ali Kimbrough (left) and Jennifer Wurtzel (2nd from right). Kelly Strzepek, the 2013 Robert Hill Memorial Prize winner, is on the right.

The high standing of group members was recognized with awards and honours during the year. Dr Abram received the Australian Academy of Science 2015 Dorothy Hill Award for women in the earth sciences in recognition for advances in our understanding of Earth’s climate system. Claire Krause was awarded the RSES Robert Hill Memorial Prize for outstanding research and communication in the earth sciences. Her commitment to effective communication included attendance at “Science Meets Parliament 2015” and a two-day internship at Parliament House at the invitation of the Honourable Adam Brandt (Greens MP).

Three of our PhD students presented talks at the 19th INQUA Congress (held in Nagoya, Japan) with financial support from an ANU Vice Chancellor Travel Award (Ali Kimbrough), an RSES DA Brown Travel Award (Jennifer Wurtzel) and AQUA Student Travel Prizes (Jennifer Wurtzel, Claire Krause). Dr Gagan was an invited speaker at the AGU Fall Meeting (held in San Francisco, USA).

Research Highlights

The diversity and novelty of our research achievements in 2015 were well illustrated in several publications. A notable highlight was PhD scholar Claire Krause’s role in an international team that examined the extent and expression of the Antarctic Cold Reversal in the Southern Hemisphere using a synthesis of 84 palaeoclimate records (published in Nature Geoscience). Dr Abram led a comprehensive assessment of location and length considerations for optimised coral reconstructions of the Indian Ocean Dipole (in Paleoceanography) with contributions by previous student researchers Bronwyn Dixon, Madi Rosevear and Ben Plunkett. She also co-authored a synthesis of tropical sea surface temperatures for the past four centuries by the PAGES Ocean2k consortium (also in Paleoceanography). Dr Gagan and colleagues described a novel palaeogeodetic method in Earth and Planetary Science Letters that utilises abrupt changes in coral 13C/12C records to detect coseismic seafloor displacement during megathrust earthquakes west of Sumatra. He also led the publication (in Palaeo3) of the serendipitous discovery of a cave-chamber hidden below Liang Bua on Flores with the potential to extend our knowledge of Homo floresiensis. Dr Opdyke co-authored a paper in Nature Communications showing links between the late deglacial warming history of Antarctica and the evolution of the Australian monsoon.

New Appointments and Service

Dr Gagan accepted a three-year appointment to the Scientific Advisory Board at the Earth Observatory of Singapore, Nanyang Technological University. Dr Abram took-up three new service roles in 2015: member of the Australian Academy of Science’s National Committee for Earth System Science; co-chief editor for Climate of the Past; and joined the PAGES2k coordination team. Dr Opdyke was appointed to the position of RSES Honours Coordinator. Dr Burne served as Guest Professor in the Centre for Advanced Physics, University of Chongqing, and also as an Honorary Professor in the Department of Earth Sciences, University of Queensland where he is co-supervisor of Anderson Chagas, a PhD student on secondment from PETRBRAS working on microbialites of Lake Hawden, South Australia.

Laboratory Developments

Laboratory developments are underway along two fronts. Dr Abram is leading an ANU Major Equipment Committee bid for a portable Picarro high-precision water isotope analyser, and the group is formulating an ARC LIEF bid, led by ARC Laureate Fellow Eelco Rohling, to purchase mass spectrometer facilities dedicated to clumped isotope geochemistry.

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