Antarctic Deep Water Circulation and Continental Weathering from the Eocene Greenhouse to the Oligocene Icehouse (IODP Expedition 318, Wilkes Land).

Lead Research Organisation: Imperial College London
Department Name: Earth Science and Engineering

Abstract

We are currently living in a world of climate change. Global atmospheric concentrations of carbon dioxide are rising at a rate unprecedented in the history of the Earth, and there is no doubt that a large part of this rise is due to human acitivity. Our ability to predict the effects of increased CO2 concentrations in the atmosphere and associated warming, heavily depends on understanding the relationship between physical, chemical, and biological processes in the Earth system, which are intrinsically coupled to temperature and atmospheric CO2 through so called 'feedback mechanisms'. But how can we study such mechanisms? One important aspect is to study how the modern climate system operates, by direct observations. However, such observations can only cover time spans, which are relatively short. To see the full swings of the climate system, we need to go beyond human observations and look at climate archives of the past, such as sediment cores recovered from the bottom of the ocean. More than 30 years of internationally coordinated ocean drilling has retrieved drillcores containing climate records from hundreds of locations all across the ocean basins, reaching back in time more than 100 million years. Reconstruction of various parameters of the climate system from such cores, such as ocean temperatures, intensity of continental weathering, or past ocean circulation patterns, has provided valuable insights into the climate system, existing feedback mechanisms and how they operated in the past. The most significant (natural) climate swing of the past 65 million years was the transition from the Greenhouse world, characterised by subtropical conditions even at high latitudes (Arctic and Antarctic; ~50 million years ago) to the icehouse world we are currently living in (i.e., warm temperature at low latitudes, cold temperatures at high latitudes; started ~33 million years ago). To understand this climate transition, we have to study what actually happened at high latitudes. Expedition 318 of the Integrated Ocean Drilling Program (IODP) took on this challenge and aimed to drill for the first time in 10 years sediment cores close to the Antarctic continent. Drilling in the vicinity of Antarctica is a technically challenging task due to weather and ice conditions, but also due to the nature of the often coarse-grained sediments at the seafloor. Expedition 318 took place in January to March 2010, and what we came back with is a spectacular record of sediments that tells us a story about peak greenhouse conditions, the earliest moments of the icehouse world, and the history of the Antarctic ice sheet all the way from ~30 million years ago to today. While this material will enable us to address many longstanding questions in climate change, it is especially noteworthy that this is the first time peak greenhouse sediments have been recovered from an area proximal to the East Antarctic coast. These sediments, together with the ones characteristic of the first moments of the icehouse world, build the center of our proposed study. We developed a research plan to study continental weathering and ocean circulation, two of the key climate variables, in the new cores. Our results will build a critical step in developing a more comprehensive understanding of drivers, amplifiers, and feedbacks in the climate system.

Publications

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Bijl PK (2013) Eocene cooling linked to early flow across the Tasmanian Gateway. in Proceedings of the National Academy of Sciences of the United States of America

 
Description Our data show that a tropical environment prevailed on the Antarctic continent during the Eocene warmth some 50 million years ago (e.g. palm trees in coastal areas). The first continental scale ice sheets reached the margin of Wilkes Land margin some 34 million years ago, and this transition into an icehouse world led to a fundamental change in Southern Ocean ecosystems. From then on the large ice sheet was not stagnant but waxing and waning under the heart beat of well-known natural climate cycles due to the earth's orbit around the sun and resulting changes in solar insolation . Our analyses of the chemical composition and make-up of the sediments drilled off Antarctica tell a story of a pronounced change in climate conditions around Antarctica over the past 50 million years.



The project furthermore delivered supporting evidence for a palynology study that documents (sub)tropical conditions on Antarctica's low lying margins during the warm Eocene (~50 million years ago) and an ecosystem study demonstrating the onset of modern-like ecosystems in the Southern Ocean after the Eocene-Oligocene boundary. Ocean circulation reconstructions throughout the greenhouse-icehouse transition showed some interesting results in that we found strong indication for deep and bottom water production around the Antarctic margin, even during times of pronounced warmth, making the case for convection in high latitudes due to seasonal temperature contrasts.
Exploitation Route We are working on further developing isotope geochemical sediment provenance analyses as a tool in the icehouse world to constrain ice extent on Antarctica. Our results across a variety to timescales provide the first ice-proximal records for some of the periods discussed and are hence invaluable for understanding the bigger picture of climate change and the response of ice sheets to different environmental conditions.
Sectors Education,Environment

 
Description The results on palm trees growing on coastal Antarctica some 50 million years ago have been all over the media, and definitely contributed to educating the general public on natural climate change questions.
First Year Of Impact 2012
Sector Environment
Impact Types Societal

 
Description Antarctic ice sheet history revealed by marine sediment provenance
Amount £9,900 (GBP)
Funding ID IE110878 
Organisation The Royal Society 
Sector Academic/University
Country United Kingdom
Start  
 
Description Deglacial ice dynamics in the Weddell Sea embayment using sediment provenance
Amount £320,000 (GBP)
Funding ID ANT 1342213 
Organisation National Science Foundation (NSF) 
Sector Public
Country United States
Start 10/2014 
End 09/2017
 
Description ESSAC-ECORD Research Grant
Amount £1,600 (GBP)
Organisation European Consortium for Ocean Research Drilling (ECORD) 
Sector Public
Country European Union (EU)
Start 01/2014 
End 12/2014
 
Description History of the East Antarctic ice sheet since the mid-Miocene: new evidence from provenance of ice-rafted debris
Amount £215,029 (GBP)
Funding ID ANT 0944489 
Organisation National Science Foundation (NSF) 
Sector Public
Country United States
Start  
 
Description Ocean-ice Interaction in the Ross Sea during Past Warm Periods
Amount £25,152 (GBP)
Funding ID NE/R018219/1 
Organisation Natural Environment Research Council 
Sector Public
Country United Kingdom
Start 04/2018 
End 12/2019
 
Description Reconstructing the stability of the Antarctic ice sheets
Amount £250,000 (GBP)
Organisation A Foundation 
Sector Charity/Non Profit
Country United Kingdom
Start 10/2014 
End 09/2018
 
Description Major and trace element analysis 
Organisation Open University
Country United Kingdom 
Sector Academic/University 
PI Contribution Analysis of fish teeth for their Nd isotopic composition.
Collaborator Contribution Analysis of fish teeth for their major and trace element composition.
Impact Numerous publications across a range of projects.
Start Year 2013
 
Description Atmosphere exhibiton 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Helped with scientific advise during the design phase of the atmosphere exhibition in the Science Museum (opened in autumn 2010).

I take now every year our new first year students to the exhibition and make them present on some aspect of the atmosphere exhibition. It is well received by visitors of the museum.
Year(s) Of Engagement Activity 2010
 
Description Blog from IODP expedition 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact I run a blog reporting live from IODP expedition 318 to Wilkes Land, Antarctica.

Many enthusiastic comments about my blog from friend, family, students, and the general public.
Year(s) Of Engagement Activity 2010
 
Description Chasing Ice 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Panelist on a screening of the documentary 'Chasing Ice' at Imperial College London.

The audience was stunned by the wonderful pictures presented in this film, but also by the scientific facts revealed by it. They appreciated the presence of science experts on the topic to follow up their questions.
Year(s) Of Engagement Activity 2013
 
Description EGU poster presentation 2011 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Poster presentation at the EGU 2011 in Vienna, on 'Bulk sediment geochemistry as a tool in palaeoclimate studies; preliminary results from shipboard analyses of IODP Expedition 318' highlighting the value of shipboard bulk sediment geochemistry for preliminary interpretations.

Positive comments on modification of IODP protocols for shipboard geochemistry on palaeoceanography legs.
Year(s) Of Engagement Activity 2011
 
Description Earthclass 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Schools
Results and Impact Annual open day event by the Department of Earth Science and Engineering to educate school kids on Earth Science topics.

The children loved to see how you can take a fish tank, partnered with a bit of salty water, ice cubes and heating elements, and produce ocean circulation.
Year(s) Of Engagement Activity 2011,2012
 
Description Evening talk 2013 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Evening talk on Antarctic Science at the Amateur Geological Society in London.

Good follow up discussions.
Year(s) Of Engagement Activity 2013
 
Description History of Antarctic drilling video 
Form Of Engagement Activity A broadcast e.g. TV/radio/film/podcast (other than news/press)
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Participated in filming for a video on the history of Antarctic drilling.
Year(s) Of Engagement Activity 2018
URL https://www.youtube.com/watch?v=GN9faSiGUZQ
 
Description Imperial College Podcast for release of Nature paper 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Audio podcast related to the release of the Pross et al. (2012) paper in Nature.

People still come up to me and say 'where there really palm trees in Antarctica some 50 million years ago? how do you know?'. It has been a great story to communicate to the general public and to explain how palaeoclimate research works.
Year(s) Of Engagement Activity 2012
 
Description London International Youth Science Forum 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Schools
Results and Impact Outreach talk on Antarctic Science at the London International Youth Science Forum

Enthusiastic response from participating pupils.
Year(s) Of Engagement Activity 2010
 
Description MAGIC Elements 
Form Of Engagement Activity Participation in an open day or visit at my research institution
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Hundreds of under-12s visited the Imperial Festival stand on MAGIC Elements with their parents. They dressed up as scientists, learned about elements and isotopes, and even about how Antarctica once was a continent with palm trees at its shorelines.
Year(s) Of Engagement Activity 2018
URL https://www.imperial.ac.uk/news/185986/imperial-festival-transforms-under-12s-into-mini/
 
Description Media contact Grantham 
Form Of Engagement Activity A press release, press conference or response to a media enquiry/interview
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Part of a small group of Grantham affiliates that helps with media requests. My expertise is in the are of palaeoclimate and Antarctic ice sheets
Year(s) Of Engagement Activity 2016,2017,2018,2019
 
Description Open Day 2014 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Schools
Results and Impact Talk about Earth Science at College wide Open Day.

Hopefully it inspires pupils to come and study Earth Sciences!
Year(s) Of Engagement Activity 2014
 
Description Pint of Science 2014 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? Yes
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Outreach talk in a pub to explain science to the general public in a friendly environment.

Sparked great discussions on Antarctic ice sheets and sea level change under future climate conditions.
Year(s) Of Engagement Activity 2014
 
Description Pint of Science 2018 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Public/other audiences
Results and Impact Outreach talk in a pub to explain science to the general public in a friendly environment.
Year(s) Of Engagement Activity 2018
URL https://pintofscience.co.uk/event/understanding-antarctica
 
Description Shipboard outreach program 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact A number of weekly videos as well as a trailer and an expedition summary were produced by a professional videographer on the JOIDES Resolution and were distributed via YouTube.

Gained lots of enthusiastic responses and marked a novel way to do outreach on an IODP expedition.
Year(s) Of Engagement Activity 2010
 
Description Twitter 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact Tweets about climate change, Antarctica, women in science, STEM related topics and (Earth) Science in general.
Year(s) Of Engagement Activity 2014,2015,2016,2017,2018
 
Description UK Antarctic Research talk 2014 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Overview talk on the provenance work on Antarctic ice sheets.

Was received well by the Antarctic research community.
Year(s) Of Engagement Activity 2014
 
Description UK IODP conference 2014 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Keynote speaker at the UK IODP conference. Reported results of IODP Expedition 318 to date.

Great feedback on how successful this particular expedition was, and great discussions about the work done in my group.
Year(s) Of Engagement Activity 2014
 
Description evening lecture 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Evening talk at the Harrow and Hillingdon Geological Society in NE London on 'Reconstructing the history of the Antarctic ice sheet. Clues from the past for the future?'

Talk lead to a very good discussion with the members of the society and a follow up write-up in their monthly newsletter.
Year(s) Of Engagement Activity 2011