Scientific drilling beneath the oceans solves earthly problems

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					Scientific drilling beneath the oceans                                Australian Journal of Maritime and Ocean Affairs (2010) Vol 2(2)



Scientific drilling beneath the oceans solves earthly
problems
Neville Exon*


Abstract
Australia and New Zealand are partners in the world’s largest international geoscience program, the
Integrated Ocean Drilling Program (IODP), which involves both geoscientists and microbiologists. IODP takes
sediment and rock cores from as deep as several kilometres below the sea bed, in order to explore how the
Earth has worked in the past and how it is working now. Many ocean drilling expeditions have been carried out
in our region since the early 1970s and a great amount of fascinating scientific knowledge of global
significance has been gained.
                                         ______________________________________________


The importance of ocean drilling to a marine                           We have one of the world’s largest marine
audience                                                               jurisdictions (larger than onshore Australia) to study
                                                                       and manage, and marine geoscience plays a key role
The Integrated Ocean Drilling Program (IODP) is a
                                                                       in both environmental and resource assessment.
program of exciting science but some parts of that
                                                                       Australia has present claims to about 14 million km²
science are of more immediate interest to a general
                                                                       of offshore territory,1 consisting of 11.65 million
audience than others; of especial interest are the
                                                                       km² off Australia that is accepted by the
studies of past changes in climate, ocean currents
                                                                       Commission of the Limits of the Continental Shelf,
and sea level, which can help us better predict the
                                                                       and our Extended Economic Zone off Antarctica of
future. Ocean drilling is complementary to the study
                                                                       2.21 million km²; the maximum potential claimable
of ice cores, which provides information about past
                                                                       area is about 15 million km². Under the United
atmospheric changes but not oceanic changes, and
                                                                       Nations Convention on the Law of the Sea 1982
which is limited to very high latitudes (Antarctica
                                                                       arrangements, we need to understand and manage
and Greenland), whereas ocean drilling has and is
                                                                       our offshore jurisdiction; the understanding must be
being carried out from the Equator to Antarctica and
                                                                       based largely on marine science. For this purpose
the Arctic Ocean. The other area of high general
                                                                       we actually need more scientists than we have,
interest is the study of natural hazards; the history of
                                                                       specialised equipment that we do not have, and
volcanic outbursts can inform our understanding of
                                                                       vessels with capabilities that Australian research
future hazards and the planning for them. The
                                                                       agencies do and will not possess. The planned
drilling study of the mechanisms of earthquakes
                                                                       Australia research vessel, The Investigator, will
associated with oceanic trenches, including
                                                                       improve our situation considerably but will still not
instrumenting the fault zones, can help us to better
                                                                       be capable of some important research activities.2
understand how the earthquakes occur and hopefully
                                                                       There is a new government emphasis on marine
to help predict them in the long term.
                                                                       matters as exemplified by recent initiatives such as
Australia and Marine Science                                           the recently released A Marine Nation: National
                                                                       Framework for Marine Research and Innovation
Australia is a small but influential player in                         report.3
international marine science, including its role
within IODP.
                                                                       1
                                                                           Philip Symonds, Mark Alcock and Colin French, ‘Setting
                                                                           Australia’s limits: understanding Australia’s marine
* Professor Neville Exon is the Program Scientist in charge of             jurisdiction’, AUSGEO News 93, March 2009, p. 7,
  the Australian and New Zealand IODP Office at the Research               <www.ga.gov.au/image_cache/GA13583.pdf>       (26   July
  School of Earth Sciences at the Australian National                      2010).
                                                                       2
  University in Canberra. He has wide experience in land                   CSIRO media release 09/82, $120 million for new Marine
  geology and marine geology and geophysics, and has written               Research Vessel, 12 May 2009, <www.csiro.au/news/New-
  successful proposals for and participated in past                        marine-research-vessel> (26 July 2010).
                                                                       3
  ocean drilling expeditions. He is also part of the Technical             See Australian Government Oceans Policy Science
  Advisory Group for the new deepwater Australian research                 Advisory Group, A Marine Nation: National Framework for
  vessel The Investigator. He can be contacted at                          Marine Research, Bureau of Meteorology, Melbourne,
  Neville.Exon@anu.edu.au or by phone on 02 6125 5131.                     2009, <www.opsag.org/pdf/opsag-marine-nation-01.pdf> (26

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Scientific drilling beneath the oceans                          Australian Journal of Maritime and Ocean Affairs (2010) Vol 2(2)


We have natural advantages in marine geoscience                  holes across fault zones that generate earthquakes
because, along with New Zealand, we are probably                 and tsunamis, with the aim of better understanding
the major players in the southern hemisphere and are             earthquakes, and ideally predicting them and thus
the only IODP members in this hemisphere.                        saving untold numbers of human lives. This
Fortunately, international research institutes are               technology could perhaps be used later west of
already heavily involved in cooperation with                     Sumatra – we all know of the devastating
Australian groups (government agencies and                       earthquakes and tsunamis generated there.4
universities) in the field. It should be noted that
there is strong cooperation between geoscience and               What is IODP?
other disciplines such as physical oceanography and              The sediments and rocks beneath the world’s oceans
marine biology.                                                  contain a remarkable story of how the Earth works
                                                                 now and has worked in the past, and suggestions
The Nature of Marine Geoscience
                                                                 about how it may work in the future. Australian
Marine geoscience involves examining the nature of               geoscientists and microbiologists are involved in
the sea bed and the processes shaping it, and the                studies of cores taken through these sediments and
nature and mineral resources of all that lies beneath            rocks, using the latest technology from the IODP,
the sea bed. The nature of the sea bed is of vital               which is the world’s largest multinational
importance to the food chain that is based on it and             geoscience program.5 The rationale for these studies
hence to our wild fisheries and aquaculture. The                 includes the realisation that the past is often a key to
sediments below the sea bed tell us about past                   the future of the Earth.
environments, and host resources such as petroleum,
                                                                 IODP controls drill ships worth roughly US$1
metallic ore deposits of various types, and sand and
                                                                 billion, and has an annual working budget of about
gravel that are vital to our future. Offshore
                                                                 US$210 million for the United States fiscal year.6
petroleum is one of Australia’s largest export
                                                                 The primary exploration tools are dynamically-
earners, and its discovery depends on geoscience.
                                                                 positioned Japanese and American coring vessels
Much geoscience work involves remote sensing,                    but, where the primary vessels are not suitable, the
such as acoustic swath mapping to map the sea bed,               European Union through the European Consortium
reflection seismic profiling to reveal the structures            for Ocean Drilling Research (ECORD) charters
(and by inference, resources) below the sea bed, and             other coring platforms. The available equipment can
the taking of sediment cores to study climate                    take continuous sediment or rock cores in all oceans,
history. It also includes taking sea bed samples on              in most water depths and up to 5000m below the sea
steep slopes where the ancient strata of sedimentary             bed. Deepwater drilling has been likened to drilling
basins are exposed, thus giving us a better                      into the pavement with a string of spaghetti from the
understanding of those basins and their petroleum                top of the Empire State Building.
potential.
                                                                 Onboard ship, an average of 30 scientists and 30
A completely different field is the study of active              technicians from around the world works around the
and extinct volcanoes in island arcs and adjacent to             clock on the cores. They have an array of laboratory
oceanic trenches, both to better understand them and             and other research equipment aboard the primary
the hazards they present, and also to study modern               vessels that few Australian university departments
gold and copper deposits, not only for their own                 can match. A single two-month expedition can
worth but also to better understand and predict                  recover thousands of metres of cores, which keep 30
ancient deposits that formed in the ocean but that are           or more scientists busy for several years. A host of
now on land.                                                     publications appear in the open scientific literature
                                                                 2-3 years after each expedition, and the IODP’s own
IODP coring is the ultimate tool to study many of
                                                                 scientific reports on expeditions are publicly
these matters deep below the sea floor. For example,
off Japan the hazards from earthquakes are well
known and devastating. There, IODP will place
                                                                 4
geophysical, pressure and chemical sensors in bore                   Phil Cummins and Mark Leonard, ‘The Boxing Day 2004
                                                                     Tsunami – a repeat of 1833?’, AUSGEO News 77, March
                                                                     2005, pp. 3-5, <www.ga.gov.au/image_cache/GA6137.pdf>
                                                                     (26 July 2010).
                                                                 5
  July 2010); and Kate Wilson, Providing a framework for             See the Integrated Ocean Drilling Program website
  our Marine Nation, Australian Government Oceans Policy             <www.iodp.org> (2 July 2010).
                                                                 6
  Science Advisory Group, <www.opsag.org/powerpoint/                 IODP, Annual Program Plan FY2009, pp 7-8,
  090617-AmericanChamberOfCommerce-OPSAG-KWilson.                    <www.iodp.org/index.php?option=com_docman&task=doc_
  ppt> (26 July 2010).                                               download&gid=2416> (26 July 2010).

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Scientific drilling beneath the oceans                                Australian Journal of Maritime and Ocean Affairs (2010) Vol 2(2)


    Figure 1: Map showing the locations of IODP scientific drilling until mid 2010.




                                                   Courtesy H.C. Larsen, IODP-MI


available,7 and an example of a mature publication                           of Australia; drilling to the earth’s mantle; and
covers the results of scientific drilling off Tasmania                       understanding earthquakes and tsunamis.
in 2000.8
                                                                       •     The deep biosphere and ocean floor.
IODP’s main research fields are:                                             ‘Extremophile’ microbes have been shown to
                                                                             live deep beneath the sea floor. In total they
•     Environmental change processes and effects.
                                                                             have an enormous biomass, and they could be of
      This covers past rapid climate change and
                                                                             industrial importance. Accumulations of frozen
      extreme climates, climatic cycles, and the
                                                                             gas hydrates (largely methane) beneath the sea
      evolution of oceanic currents and boundaries.
                                                                             floor are a huge potential energy resource and
      Ocean drilling has been and will be a key to
                                                                             their release has been shown to trigger bursts of
      understanding past climate change on all time
                                                                             global warming in the past.9
      scales and at many locations, and hence in
      helping to predict future climate changes.                       Studies of past changes in climate and global sea
                                                                       level, and of past volcanic eruptions, are obviously
•     Solid earth cycles and geodynamics. This
                                                                       of great immediate societal relevance. In this area
      deals with continental breakup and sedimentary
                                                                       the past can illuminate the future. Climate change
      basin formation, which is especially important
                                                                       and sea level rise are pressing issues, and some of
      in petroleum exploration; large igneous
                                                                       the best evidence about past variations and what
      provinces like the Kerguelen Plateau southwest
                                                                       appears to have driven them comes from ocean
                                                                       drilling cores. Evidence of the size, damage caused
7
    See IODP Scientific Publications <www.iodp.org/scientific-         by, and frequency of past volcanic eruptions can
    publications> (26 July 2010).
8
    NF Exon, JP Kennett, MJ Malone (eds), The Cenozoic
                                                                       9
    Southern Ocean: Tectonics, Sedimentation and Climate                   Integrated Ocean Drilling Program Initial Science Plan, 2003-
    Change between Australia and Antarctica. American                      2013, Earth, Oceans and Life: Scientific Investigation of the
    Geophysical Union, Geophysical Monograph Series 151,                   Earth System using Multiple Drilling Platforms and New
    2004.                                                                  Technologies, <www.iodp.org/isp> (2 July 2010).

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Scientific drilling beneath the oceans                               Australian Journal of Maritime and Ocean Affairs (2010) Vol 2(2)


 Table 1. ANZIC participants on IODP expeditions

   Expedition                                         Date                      Participant

   NanTroSeize 1: 316                                 December 2007 -           Chris Fergusson (University of Wollongong),
   Nankai Trough Faulting                             February 2008             sedimentology

   PEAT 1: 320                                        5 March -                 Christian Ohneiser (Otago University),
   Eastern Pacific environments                       5 May 2009                palaeomagnetism

   Bering Sea: 323                                    5 July -                  Kelsie Dadd (Macquarie University),
   Connections from Pacific to Arctic                 4 September 2009          sedimentology of volcanic ash

   Shatsky Rise: 324                                  4 September -             David Murphy (QUT), petrology of volcanics
   Volcanic buildup: NW Pacific                       4 November 2009

   NanTroSeize 2: 319                                 10 May -                  Gary Huftile (QUT), structural geology
   Nankai Trough deep observatory                     31 August 2009

   NanTroSeize 2: 322                                 5 September -             John Moreau (Melbourne University), microbiology
   Nankai Trough Subduction                           10 October 2009

   Great Barrier Reef: 325                            11 January -              Jody Webster (Sydney University), Co-Chief
   environmental change caused by post-glacial sea    5 March 2010              Scientist, reef formation
   level rise

   Canterbury Basin: 317                              4 November 2009 -         Bob Carter (JCU), Simon George (Macquarie), Greg
   sea level fluctuations in last 20 million years    4 January 2010            Browne, Martin Crundwell (GNS), Kirsty Tinto
                                                                                (Otago)

   Wilkes Land: 318                                   4 January -               Kevin Welsh (Queensland) and
   climate and oceanographic changes in last 53       9 March 2010              Robert McKay (Victoria University, Wellington),
   million years                                                                both sedimentology

   South Pacific oceanic gyre microbiology. East of   8 October -               Jill Lynch (Melbourne University), microbiology
   New Zealand                                        12 December 2010

   Louisville Seamount geodynamics. Southeast of      12 December 2010 -        Ben Cohen (Queensland University), volcanic
   Tonga                                              11 February 2011          petrology, David Buchs (ANU), volcanic
                                                                                sedimentology



also be found in such cores and used to help predict                    only those that address global problems in
the future. Although IODP is designed as a program                      particularly suitable areas have any chance of
of pure science, a better understanding of the                          success. The membership of IODP is led by the
sedimentary sequences of poorly known continental                       United States, Japan and Europe, and the other
margins is important to the petroleum exploration                       countries involved are Australia, Canada, China,
industry. Previous ocean drilling in the Exmouth                        India, New Zealand and the Republic of Korea.
Plateau off the Australian northwest shelf, and off
                                                                        A map showing the location of IODP drilling since
Tasmania, has helped companies better understand
                                                                        2004 indicates just how geographically widespread
some aspects of the petroleum potential of these
                                                                        were the various expeditions. Before the present
regions, thus better focusing their efforts on
                                                                        phase of ocean drilling ends in 2013, more work will
petroleum search. Successful petroleum search is in
                                                                        be done in the Pacific, Atlantic and Indian oceans.
the nation’s interest, because it increases our self
sufficiency and decreases our import costs.                             The Australian and New Zealand IODP
IODP coring tests global geoscientific theories that                    Consortium
are often developed largely on the basis of remote                      Australia and New Zealand form the Australian and
sensing. New technologies and concepts in                               New Zealand IODP Consortium (ANZIC), and the
geoscience are continuously being developed                             two countries have access to all IODP activities
through IODP. Proposals for drilling are rigorously                     including shipboard and post-cruise research,
assessed under intense international competition and

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Scientific drilling beneath the oceans                                    Australian Journal of Maritime and Ocean Affairs (2010) Vol 2(2)


participation in planning committees and groups,                                  later covered in sediment, thus contributing
and visits from outstanding scientific speakers. The                              greatly to the concept of plate tectonics.
Australian involvement is supported by the
                                                                           •      Proving that the oceanic rocks existing at
Australian Research Council (ARC), 14 universities
                                                                                  present have all formed in the last 200 million
(Adelaide, ANU, Curtin, James Cook, Macquarie,
                                                                                  years, and showing that such rocks are
Melbourne, Monash, Newcastle, Queensland, QUT,
                                                                                  continuously poured out at mid-oceanic ridges
Sydney, Tasmania, Western Australia, and
                                                                                  and destroyed at oceanic trenches. Continental
Wollongong), CSIRO, ANSTO and AIMS, and
                                                                                  rocks, by contrast can be billions of years old.
MARGO (a marine geoscience peak body). The
                                                                                  Many of these ‘continental rocks’ are, in fact,
Australian annual budget is almost $2.2 million, of
                                                                                  ancient sedimentary and volcanic rocks that
which the ARC provides $1.55 million.10
                                                                                  formed in the ocean but have been accreted to
Membership of IODP helps Australia and New                                        the continents.
Zealand maintain our leadership in southern
hemisphere marine research. For geographic,                                •      Providing a detailed history of the climate and
climatic, oceanographic and plate tectonic reasons,                               oceanographic changes that have affected the
our region is vital to addressing various global                                  world’s oceans in the last 200 million years.
science problems, and some of them cannot be                               This was the exploration phase of ocean drilling,
addressed elsewhere. Accordingly, the Australasian                         with holes being drilled in most parts of the world’s
region has seen a great deal of ocean drilling since                       oceans to test existing ideas and also to see what
1968, when the first program was established.11                            actually was there. A great deal was learned about
Although drilling in the Australian region has ended                       the volcanic ridges and the intervening sedimentary
for the time being, our scientists have and will be                        basins that characterise the sea floor in our region,
involved in a variety of expeditions elsewhere in the                      and about the plate tectonic history of Australia. It
world, addressing global scientific problems.                              was shown that other Gondwanan continents broke
Australian scientists gain in various ways: through                        away from Australia, starting about 160 million
shipboard and post-cruise participation in cutting                         years ago, with Australia moving north from
edge science, by building partnerships with overseas                       Antarctica in the last 90 million years.
scientists, by being research proponents and co-chief
scientists who can steer programs and scientific                           Early Maturity: The Ocean Drilling Program
emphasis, and by early access to key samples and
                                                                           In 1985, a larger and more capable new drilling
data. Post-doctoral and doctoral students have an
                                                                           vessel, the JOIDES Resolution, replaced the Glomar
opportunity of training in areas of geoscience and
                                                                           Challenger in the new Ocean Drilling Program
microbiology that could not be obtained in any other
                                                                           (ODP). This phase of ocean drilling was still largely
way.
                                                                           funded by the United States, but considerable funds
                                                                           were provided by European countries and Japan, and
Early Days: The Deep Sea Drilling Project
                                                                           Australia joined as an associate member in a
Between 1968 and 1983, the Deep Sea Drilling                               regional consortium in 1988.12 Although scientists
Project (DSDP) began the study of the deep ocean                           from member countries took up most positions on
sediments and rocks using the Glomar Challenger.                           vessels, scientists from countries that were not
DSDP was funded by the US National Science                                 members, but where drilling was taking place, also
Foundation but welcomed foreign scientists,                                participated. Australian scientists were heavily
including Australians and New Zealanders, to its                           involved both before Australia joined and afterward,
drilling campaigns. This ship started to build a story                     and New Zealand scientists were commonly
about what was happening and had happened in the                           involved near New Zealand although New Zealand
70 per cent of the Earth’s crust that lies beneath the                     was not a member. By the time ODP ended in 2003,
oceans. Its major achievements included:                                   there had been 17 two-month expeditions in our
                                                                           region (13 in Australian waters), 71 Australian
•      Drilling and dating the oceanic basalts that form
                                                                           scientists had participated in expeditions, and 7
       on the sea floor as continents drift apart and are

10
     See the Australian Integrated Ocean Drilling Program
     website <www.iodp.org.au> (2 July 2010).
11
     Integrated Ocean Drilling Program Initial Science Plan, 2003-
                                                                           12
     2013, Earth, Oceans and Life: Scientific Investigation of the              Elaine Baker and Jock Keene, Full Fathom Five – 15 years of
     Earth System using Multiple Drilling Platforms and New                     Australian involvement in the Ocean Drilling Program,
     Technologies, <www.iodp.org/isp> (2 July 2010).                            WYSIWIG DESIGN, Sydney, 2004.

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Scientific drilling beneath the oceans                                    Australian Journal of Maritime and Ocean Affairs (2010) Vol 2(2)


      Figure 2:    Chikyu at sea. This huge drillship can drill in water 2500m deep, and is designed to take cores up to 6000m
                   below the sea bed.




Australian scientists had acted in the key position of                     purposes) Chikyu.14 The Europeans charter
co-chief scientist.13                                                      specialised drilling vessels for occasional
                                                                           expeditions where neither of the other two vessels
This was a phase of ocean drilling which aimed to
                                                                           has the right capability.15 This means that drilling in
solve global scientific problems, rather than one of
                                                                           the Arctic Ocean and in shallow reefal areas, for
curiosity-driven exploration like DSDP. Numerous
                                                                           example, is now possible.
Australians were proponents of successful proposals
and the Australian geoscience research vessel, Rig
                                                                           Recent IODP expeditions: western Pacific Ocean
Seismic, was instrumental in carrying out the
                                                                           and Southern Ocean
detailed site surveys that were essential for
successful proposals. When Rig Seismic was                                 Australians and New Zealanders have recently been
disposed of by the Australian Geological Survey                            involved in various expeditions using three vessels.
Organisation (AGSO) in 1998, Australia no longer                           In 2009, six Australian scientists and one New
had the world-class seismic profiling capability                           Zealander sailed on expeditions in the northern
needed for most site survey work.                                          Pacific. An Australian led the microbiological
                                                                           program on an expedition off Japan – the first
Maturity: The Integrated Ocean Drilling
                                                                           Australian to sail in this role in the history of ocean
Program
                                                                           drilling. The giant Japanese drillship, Chikyu, has
IODP has access to more drilling platforms than the                        and will be drilling south of Japan to investigate the
one that ODP had, but the JOIDES Resolution is still                       geology of the oceanic trench where the Pacific
a very important part of the drilling capability, along                    Ocean crust is plunging beneath the Japanese
with the larger and more capable (for some                                 islands, causing devastating earthquakes and

                                                                           14
                                                                                See       American        vessel  JOIDES       Resolution
                                                                                <http://joidesresolution.org/> (2 July 2010); Japanese
13
     Integrated Ocean Drilling Program Initial Science Plan, 2003-              information on the drill vessel Chikyu and its program
     2013, Earth, Oceans and Life: Scientific Investigation of the              <www.jamstec.go.jp/chikyu/eng/Expedition/NantroSEIZE/in
     Earth System using Multiple Drilling Platforms and New                     dex.html> (2 July 2010).
                                                                           15
     Technologies, <www.iodp.org/isp> (2 July 2010).                            See the ECORD website <www.ecord.org> (2 July 2010).

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Scientific drilling beneath the oceans                                  Australian Journal of Maritime and Ocean Affairs (2010) Vol 2(2)


resultant tsunamis. A better grasp of the geology,                       Figure 3: JOIDES Resolution in Hobart. This drillship can
and the installation of seismometers and other                                     drill in water 6000m deep, and take cores up to
                                                                                   2000m below the sea bed.
analytical instruments deep beneath the seabed, will
help scientists understand and perhaps even predict
earthquakes.
The large American drillship, JOIDES Resolution,
has recently drilled on two expeditions in our
region. The first is studying past climates and global
sea level fluctuations over the last 15 million years
in the especially suitable Canterbury Basin east of
New Zealand. This expedition is described in some
detail later.
The second, in the Australian-claimed Wilkes Land
region south of Australia off Antarctica, is studying
the onset of Antarctic glaciation about 33 million
years ago, and the fluctuations in glacial history
since then. Senator Kim Carr, Minister for Science
and Innovation, visited the JOIDES Resolution in
Hobart in March. He made the point that the
government strongly supports marine science
through its funding for building the new deepwater
research vessel, The Investigator, through its support
for IODP, and in other ways.16 This expedition is
also described in some detail later.
Another drilling expedition has recently used the
smaller GreatShip Maya to investigate the history of
the 120m sea level rise in the Great Barrier Reef
since the last glaciation about 18,000 years ago, and
the associated changes in water properties and in the
composition of the reef as it migrated landward. It is
clear from seabed mapping that from time to time
the reef suddenly stepped back westward to a new                         of Shinshu University in Japan. Among the
position, and it is probable that this was caused by a                   scientific party were Bob Carter of James Cook
sudden rise in sea level followed by slow rise.                          University, Simon George of Macquarie University,
Understanding what has happened to the reef as the                       George Brown and Martin Crundwell of GNS
ocean warmed and sea level rose can surely help us                       Science in Wellington, and Kirsti Tinto of
better understand what might happen to the reef in a                     Canterbury University. The following text is drawn
future warming world.                                                    largely from the Preliminary Report.17
Canterbury Basin expedition: initial results                             This expedition was devoted to understanding the
                                                                         relative importance of changes in global sea level
The Canterbury Basin Expedition (317), carried out                       versus local tectonic (uplift and erosion) and
in late 2009 in a sedimentary basin east of New                          sedimentary processes in controlling continental
Zealand’s South Island, was designed as one of                           margin sedimentary cycles. The expedition
several ocean drilling expeditions carried out                           recovered sediments deposited offshore in the last
worldwide, to look at the details of how the world’s                     35 million years, with a particular focus on the
sea level has varied over many millions of years.                        sedimentary cycles of the last 10 million years,
The vessel used was the JOIDES Resolution. The                           when global sea level change was dominated by the
co-chief scientists were Craig Fulthorpe from the                        waxing and waning of huge ice sheets on Antarctica
University of Texas in Austin, and Koichi Hoyanagi                       and, in the last 5 million years, in the northern

16                                                                       17
     Senator the Hon. Kim Carr, Research Ship Arrives with 54-                Integrated Ocean Drilling Program Expedition 317
     million-year old climate samples, Media Release, Department              Preliminary Report: Canterbury Basin sea level, February
     of Innovation, Industry, Science and Research, Canberra, 12              2010 <www.iodp.org/preliminary_report/317/317PR.PDF>
     March 2010.                                                              (2 July 2010).

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Scientific drilling beneath the oceans                          Australian Journal of Maritime and Ocean Affairs (2010) Vol 2(2)


hemisphere. Drilling in the Canterbury Basin takes               thermohaline circulation. This new mode of ocean
advantage of high rates of sediment supply, which                circulation, caused by a much greater temperature
preserve a high-frequency (0.1-0.5 million years)                gradient from the equator to the poles, followed the
record of depositional cycles. The applied value of              separation of Australia and Antarctica and the
this research is that such sedimentary cycles are                freezing of Antarctica. It and the changes in land
related to global sea level changes. The global                  configuration, largely caused by plate tectonics,
cycles are used in petroleum exploration to help                 drive a very different pattern of ocean currents, the
interpret local cycles seen in seismic reflection                ones with which we are familiar today.
profiles (cross-sections through the strata). If the
                                                                 Expedition 317 set a number of technological ocean
cycles are better understood and better dated,
                                                                 drilling records:
petroleum exploration becomes more efficient.
                                                                 •      The deepest hole drilled in a single expedition
The expedition results allow the study of the complex
                                                                        and second deepest hole in the history of
interactions of the processes responsible for
                                                                        scientific ocean drilling (Hole U1352C, 1927m).
preserving the sedimentary sequences, in a region
where an uplifting and eroding mountain chain (the               •      The deepest hole drilled by the JOIDES
Southern Alps) provides large volumes of derived                        Resolution on a continental shelf (Hole U1351B,
sediment, and strong ocean currents erode and                           1030m).
deposit those sediments. Currents have locally built
large, elongate sediment drifts or wedges. Expedition            •      The shallowest water depth for a site drilled by
317 did not drill into one of these elongate drifts, but                the JOIDES Resolution for scientific purposes
currents are inferred to have strongly influenced                       (Site U1353, 84.7m water depth).
deposition across the basin, including in locations              •      The deepest sample taken by scientific ocean
lacking prominent mounded drifts.                                       drilling for microbiological studies (Site U1352,
Sedimentary sequences covering the last 10 million                      1925m).
years were cored in a transect of three sites on the             Expedition 317 supplements previous drilling of
continental shelf (landward to basinward), and one               sedimentary sequences for sequence stratigraphic
site on the continental slope. The transect provides a           and sea level objectives, particularly drilling on the
record of depositional cycles across the shallow-                New Jersey margin of America, and in the Bahamas,
water environments that were most directly affected              but includes an expanded Pliocene (2-5 million
by sea level change. The boundaries of different                 years old) section. Completion of at least one
sedimentary sequences, provisionally correlated                  transect across a geographically and tectonically
with seismic reflectors, have been identified in cores           distinct siliciclastic-dominated (quartz, feldspar and
from each site. These help in understanding the                  other rock grains) continental margin was the
origins of sequences identified by seismic profiling,            necessary next step in deciphering the strata on this
which provide cross-sections through the earth. This             continental      margin.    Expedition     317     also
record will be used to estimate the timing and                   complements ODP Leg 181, which focused on drift
amplitude of global sea level change and to                      development in deeper water areas of the Eastern
document the sedimentary processes that operate                  New Zealand Oceanic Sedimentary System. Plans
during sequence formation. Superb sections through               are underway for another complementary drilling
the last 3 million years of sediments will yield high-           expedition on the northwest shelf off Australia.18
resolution records of recent glacial cycles in a
continental shelf setting.                                       Wilkes Land expedition: initial results
Continental slope Site U1352 has a complete                      The full scientific results of the Wilkes Land
sedimentary section from modern land-derived                     expedition (318) will not be known for several years,
sediment to hard marine Eocene limestone, with all               but the following is drawn largely from the
the associated sedimentary, biological (fossil),                 Preliminary Report.19
physical,    geochemical,     and     microbiological
information. The site also provides a record of ocean
circulation and fronts during the last 35 million
                                                                 18
years. A break in sedimentation about 30 million                      See Proposal 667 on the Integrated Ocean Drilling Program
years ago (the Marshall Paraconformity), was the                      website <www.iodp.org/index.php?option=com_docman&
                                                                      task=doc_download&gid=487> (26 July 2010).
deepest drilling target of the expedition and is                 19
                                                                      Integrated Ocean Drilling Program Expedition 318
believed to represent intensified current erosion (or                 Preliminary Report: Wilkes Land Glacial History level, April
non-deposition) associated with the initiation of                     2010 <www.iodp.org/preliminary_report/318/318PR.PDF>
                                                                      (2 July 2010).

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Scientific drilling beneath the oceans                         Australian Journal of Maritime and Ocean Affairs (2010) Vol 2(2)


The international team of scientists worked for two             preserved within the cores will document the onset
months aboard the JOIDES Resolution in early                    of cooling and the development of the first Antarctic
2010, and took cores of sediments and sedimentary               glaciers and the growth and recession of
rocks from the seafloor near the coast of Antarctica,           Antarctica’s ice sheets. Cores from one shallow site
at four drill sites. Despite negotiating icebergs, near         contain sediment alternations that can be used like
gale-force winds, and snow and fog, they managed                tree rings to sort out environmental changes –
to recover approximately 2000m of sediment core.                alternating bands of light and dark sediment record
Wilkes Land lies due south of Australia, and is                 seasonal variability during the last de-glaciation,
believed to be one of the more climate-sensitive                which began some 10,000 years ago.20
regions of the polar continent. The new core
                                                                Understanding the behaviour of Antarctica’s ice
samples collected during the expedition are unique
                                                                sheets plays a fundamental role in our ability to build
because they provide a direct record of the waxing
                                                                robust, effective global climate models, which are
and waning of the ice sheet in this region of
                                                                used to predict future climate. ‘These models rely on
Antarctica. These sediments preserve the history of
                                                                constraints imposed by data from the field’, the co-
how the ice sheets formed and interacted with
                                                                chiefs pointed out. ‘Measurements of parameters such
changes in the climate and the ocean.
                                                                as age, temperature, and carbon dioxide concentration
In response to growing concerns about our planet’s              provide invaluable inputs that help increase the
changing climate, rising global temperatures and sea            accuracy of these models. The more we can constrain
levels, and increasing concentrations of atmospheric            the models, the better they’ll perform – and the better
carbon dioxide (CO2), many scientists are looking to            we can predict ice sheet behaviour.’
Earth’s past to help predict its future. This research
                                                                What's next? The science team now embarks on a
expedition will provide critical clues to
                                                                multi-year process of onshore analyses to further
understanding one of the most dramatic periods of
                                                                investigate the Wilkes Land cores. Age-dating and
climatic change in Earth’s history – and a glimpse
                                                                chemistry studies among other analyses are expected
into what might lie far ahead in our climate’s future.
                                                                to resolve changes in Antarctica’s climate over
The poles control much of our global climate. Giant
                                                                unprecedentedly short timescales (50-20,000 years).
ice sheets in Antarctica behave like mirrors,
                                                                Data collected from the expedition will complement
reflecting the sun’s energy and moderating the
                                                                previous research from ocean drilling operations
world’s temperatures. The waxing and waning of
                                                                conducted elsewhere in the Antarctic over the last
these ice sheets contribute to changes in sea level
                                                                40 years. Together, this research will provide
and affect ocean circulation, which regulates our
                                                                important age constraints for models of Antarctic ice
climate by transporting heat around the planet.
                                                                sheet development and evolution, thereby forming
Despite their present cold temperatures, the poles
                                                                the basis for models of future ice sheet behaviour
were not always covered with ice. Like a history
                                                                and polar climatic change.
book, the sediment cores tell the story of how,
approximately 53 million years ago, Antarctica had              Great Barrier Reef Environmental Change
a warm, sub-tropical environment covered in forest.
During this same period, known as the ‘greenhouse’              The Great Barrier Reef Environmental Change
or ‘hothouse’ world, atmospheric CO2 levels were                (GBREC) Expedition (325) was carried out in early
ten times as high as those of today.                            2010. It used the dynamically positioned drilling
                                                                vessel, GeatShip Maya, and the program was
Then quite quickly, about 33.5 million years ago,               approved and closely monitored by the Great Barrier
Antarctica’s lush environment changed into an icy               Reef Marine Park Authority. The following
realm not much different from the present one. In               description is drawn largely from the Scientific
only 400,000 years – a mere blink of an eye in                  Prospectus and a post-cruise scientific press
geologic time – concentrations of atmospheric                   release.21 The expedition was designed to study the
carbon dioxide decreased greatly. Global
temperatures dropped. Ice sheets developed.
                                                                20
Antarctica became ice-bound. How did this change                     Integrated Ocean Drilling Program Expedition 318
happen so abruptly and how stable can we expect                      Preliminary Report: Wilkes Land Glacial History level, April
ice sheets to be in the future?                                      2010 <www.iodp.org/preliminary_report/318/318PR.PDF>
                                                                     (2 July 2010).
                                                                21
Combined, the cores will tell the story of                           Integrated Ocean Drilling Program Expedition 325 Scientific
                                                                     Prospectus: covering the Great Barrier Reef Environmental
Antarctica’s transition from an ice-free, warm,
                                                                     Change           expedition,         August           2009,
‘greenhouse’ world to an ice-covered, cold, dry                      <www.publications.iodp.org/scientific_prospectus/325/325S
‘icehouse’ world. Sediments and microfossils                         P.pdf> (2 July 2010); and ECORD media release, Great
                                                                     Barrier Reef corals unveil sea-level changes and climate

                                                          45
Scientific drilling beneath the oceans                                     Australian Journal of Maritime and Ocean Affairs (2010) Vol 2(2)


      Figure 4: GreatShip Maya in the Great Barrier Reef. This smaller drillship is designed to work in relatively shallow water,
                and took cores in carbonates in water as shallow as 30m on this expedition. (Photograph courtesy of ECORD).




sea level rise and sea-surface temperature warming                          •    The first objective was to reconstruct the de-
since the peak of the last glaciation about 20,000                               glaciation curve of sea level rise for the period
years ago. This will help our understanding the                                  20,000 to 10,000 ago in order to establish the
dynamics of the melting of large ice sheets and what                             minimum sea level during the Last Glacial
happened as they turned to water. Before this                                    Maximum and to assess the validity, timing, and
expedition, the only sea level records covering the                              amplitude of a number of known glacial
whole de-glaciation came from offshore drilling of                               meltwater pulses. These are thought to have
Barbados and Tahitian coral reefs. IODP Expedition                               disturbed the general oceanic circulation, which
310 (Tahiti Sea Level), which was successfully                                   was driven by temperature and salinity, and
completed in 2005 and 2006, recovered a near-                                    hence changed global climate. The meltwater
complete record of sea level change since the last                               pulses, when ice dams confining great northern
glaciation.22                                                                    hemisphere glacial lakes burst, are also believed
GBREC was designed to establish the course and                                   to have caused at least three periods of
effects of the last de-glaciation in a reef setting in a                         accelerated sea level rise, about 19,000, 13,800
tectonically inactive area. Offshore sites were cored                            and 11,300 years ago. A series of drowned reef
along transects on the Great Barrier Reef.                                       terraces had been identified before the
                                                                                 expedition, and those between 120m deep
                                                                                 (about 20,000 years ago), and 30m deep (about
     history,    19     July    2010     <www.ecord.org/p/gbrec-
                                                                                 10,000 years ago) were cored away from living
     osp_press_release.pdf> (26 July 2010).                                      coral. The terraces presumably correspond to
22
     Integrated Ocean Drilling Program, Tahiti Sea Level:                        periods of relatively slow sea level rise, with the
     Expedition 310 of the mission-specific drilling platform                    sudden jumps upslope related to meltwater
     from and to Papeete, Tahiti, French Polynesia, Sites
                                                                                 pulses.
     M0005–M0026,         6     October-16    November        2005,
     <http://publications.iodp.org/proceedings/310/310title.htm>
     (26 July 2010).

                                                                      46
Scientific drilling beneath the oceans                                  Australian Journal of Maritime and Ocean Affairs (2010) Vol 2(2)


•      The second objective was to establish the sea-                    design the next ten-year phase of IODP from 2013.
       surface temperature variation accompanying the                    Several Australians played key roles at INVEST,
       sea’s transgression at each transect. These data                  and Australia and New Zealand produced a white
       will allow the researchers to examine the impact                  paper before it. Richard Arculus of ANU is a
       of sea level changes on reef growth, geometry,                    member of the post-INVEST New Science Plan
       and biological makeup, especially during reef                     Writing Committee, as is New Zealander Peter
       drowning events, and will help improve the                        Barrett, showing the scientific regard in which we
       modelling of reef development.                                    are held. Chris Yeats of CSIRO is the only
                                                                         representative on a key structural planning group
•      The third major objective was to identify and
                                                                         from outside the United States, Japan, and the
       establish patterns of short-term paleoclimatic
                                                                         European IODP consortium. Geoff Garrett, former
       changes that are thought to have punctuated the
                                                                         CSIRO Chief Executive and now Chairman of the
       transitional period between present-day climatic
                                                                         ANZIC Governing Council, was on another
       conditions following the Last Glacial
                                                                         important committee investigating how well the
       Maximum. It is proposed to quantify the
                                                                         scientific arrangements in IODP have worked in the
       variations of sea-surface temperatures using
                                                                         last three years, and making suggestions for the
       high-resolution isotopic and trace element
                                                                         future.
       analyses on massive coral colonies. When
       possible, the researchers will try to identify                    At a recent meeting in Cambridge, California, the
       specific climatic phenomena such as El Niño-                      Science Plan Writing Committee decided on the
       Southern Oscillation in the time frame prior to                   tentative titles for four overarching themes for the
       10,000 years ago.23                                               next phase of ocean drilling:
The cores from the expedition were sampled in July                       •    Earth's Climate Systems: Extremes, Linkages
2010 in Bremen, Germany, and detailed scientific                              and Sensitivity.
work is to start now. Enough is already known of
                                                                         •    The Crust below the Ocean: Window to the
the cores to suggest that much of the planned
                                                                              Inner Earth.
science will be achieved. The post-cruise scientific
press release, produced after the sampling program,                      •    Limits of Life: Deep Life,                      Extreme
stated that cores had come from 34 holes in three                             Environments and External Forcing.
key locations on the outer edge of the Great Barrier
Reef.24 Altogether 225m of material were recovered,                      •    Earth in Motion: Sub-seafloor Observatories.
including 191m of fossil coral reef whose age varies                     Ocean drilling has proved hugely successful in
from 30,000 to 9000 years.                                               revealing past and present Earth processes, and there
                                                                         is a strong drive to continue this work in existing
Future Plans for Ocean Drilling                                          and new directions. The aim is to have a new ten-
Ocean drilling will continue in the South Pacific                        year plan in existence when IODP terminates in
Ocean east of New Zealand late this year and early                       2013. Australian and New Zealand science has
next year. Then the JOIDES Resolution will move                          profited greatly from ocean drilling, and the
away eastward from our region, but return to the                         geoscientists and microbiologists who have been
Indian Ocean until the present phase of ocean                            involved in the work thus far are dedicated and
drilling ends in 2013. The Chikyu will continue to                       enthusiastic supporters of our continuation in the
drill in the Japanese region, and an alternative                         future program.
platform may be used to drill ancient and deeply
drowned Hawaiian reefs next year.
In September 2009, there was a very large scientific
meeting (INVEST) in Germany, which started to

23
     Integrated Ocean Drilling Program Expedition 325
     Scientific Prospectus: covering the Great Barrier Reef
     Environmental     Change    expedition,    August     2009,
     <www.publications.iodp.org/scientific_prospectus/325/325S
     P.pdf> (2 July 2010).
24
     ECORD media release, Great Barrier Reef corals unveil sea-
     level changes and climate history, 19 July 2010
     <www.ecord.org/p/gbrec-osp_press_release.pdf> (26 July
     2010).

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