Report on the International Workshop for Large-scale Research Cruises
1. General information
Cruise Title:
DIO — Delve into the Indian Ocean
Moderator’s Name：K. Takai, K. Katsumata
Moderator’s Department：Department of Subsurface Geobiological Analysis and Research,
Research and Development Center for Global Change
Required cruise days (round-trip)：Approximately 300 days
Major Survey Area：Indian Ocean
Brief description of the scientific objectives and survey plan of the cruise(s) (up to 200 words)
Indian Ocean is the least known among the three oceans; Pacific, Atlantic and Indian.
After JAMSTEC large-scale cruise planning workshop, this grand cruise, named as Delve into
the Indian Ocean (DIO), is proposed with a common ambition to know major unknowns in the
world ocean and will be an important contribution to the international framework of 2nd
International Indian Ocean Expedition (IIOE 2) developed by the Intergovernmental
Oceanographic Commission (IOC) and the Scientific Committee on Oceanic Research (SCOR)
of UNESCO. The DIO cruise consists of three major initiatives and areas to explore: (1) one is
the study of the evolution of the Indian Ocean, its' structure and geological history, and its
biosphere based on investigations of water-driven mantle heterogeneity, geodynamo, tectonics,
crustal hydrothermal activities and biodiversity and biogeography of deep-sea microbial and
faunal communities in the Central Indian Ridge, Southwestern Indian Ridge, hotspots and their
flanks; (2) another is the multidisciplinary exploration of geological and oceanographic settings
in the eastern Indian Ocean (EIO) such as the seismogenic structures and the ocean upwelling
functions in the EIO and the hypoxia biogeochemistry in the Bay of Bengal and the Andaman
Sea; (3) a further one is to clarify response of Indian Ocean to the global climate change based
on oceanographic observation in the southern and central Indian Ocean. The DIO cruise is
planned as a 3-years project: in the first year (e.g., 2016), R/V Yokosuka or Kairei with HOV
Shinkai6500 or ROV Kaiko MarkIV will pursue the initiatives (1) and (2) for 100 days; in the
second year, R/V Yokosuka or Kairei with HOV Shinkai6500 or ROV Kaiko MarkIV will
continue to address the initiatives (1) and (2) for 50 days and R/V Mirai will be in charge of the
initiative (3) for 50 days; finally in the third year, a JAMSTEC new ship will complete all the
initiatives over 100 days.
Keywords (up to 5):
IIOE 2, mantle to biodiversity, climate change, seismogenic zone, hypoxia
Relationships to the JAMSTEC Mid-term program:
Directly connected with (1) Research and Development for Submarine Resources (2) Research
and Development for Global Change, (3) Research and Development for Earthquake and
Tsunami, and (4) Research and Development for Marine Biosciences declared in the JAMSTEC
Mid-term program
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2. Co-proponent
*Please add lines if necessary
Name
Organization
1
Lynne Talley
Scripps
Institution
Oceanography
2
Nobukazu Seama
Kobe University
3
Dass Bissessur
4
Olivier Pasnin
5
Greg Cowie
University of Edinburg
UK
6
Yasushi Ishihara
JAMSTEC
Japan
7
Cecilia McHugh
8
Toshiya Kanamatsu
Queens College, City Univ. of
USA
NY
JAMSTEC
Japan
9
N.D. Hananto
Indonesian Institute of Science
Indonesia
10 Chong Chen
Oxford University
UK
11
University of Hawaii
USA
12 Yudi Nurul Ihsan
Padjadjaran University
Indonesia
13 Iwao Ueki
Shinsuke
14
Kawagucci
Marie-Helen
15
Cormier
16 Toshiya Fujiwara
JAMSTEC
Japan
JAMSTEC
Japan
University of Rhode Island
USA
JAMSTEC
Japan
17 Ken Takai
JAMSTEC
Japan
18 Katsuro Katsumata
JAMSTEC
Mauritius
Oceanography
Institute
Mauritius
Oceanography
Institute
University of Tokyo
Institut de Physique du Globe de
Paris
AORI, University of Tokyo
Japan
Greg Moore
19 Prerna Roy
20 Arnaud Nicolas
21 Yukio Masumoto
Jerome Dyment
22
23 Kyoko Okino
24 Tomoaki Morishita
25 Yoshifumi Nogi
Wajih Naqvi
26
27 Hirsohi Kitazato
Country
of
USA
Japan
Mauritius Oceanography
Institute
Mauritius Oceanography
Institute
Mauritius
Mauritius
Mauritius
Mauritius
Japan
France
Japan
Kanazawa University
Japan
NIPR
Japan
National
Institute
Oceanography of India
JAMSTEC
2
of
India
Japan
Remarks
3. Scientific Objectives of the cruise(s)
We propose here a series of grand cruise project named as Delve into the Indian Ocean (DIO) for
comprehensive and interdisciplinary understanding of the least-explored ocean, the Indian Ocean,
for the evolution of whole Indian Ocean and its biosphere, the structures and functions of unique
geological and oceanographic settings in the eastern Indian Ocean (EIO) and the response of Indian
Ocean to the global climate change. The cruise comprises six components, each originating from
pre-proposals submitted under different disciplines.
(1) Road back to Vasco Da Gama (L14-05: Takai et al.; L14-16: Rogers et al.; L14-45: Copley et
al.; L14-56: Bissessur et al.). The scientific objectives of this theme are to further extend our
understanding of deep-sea hydrothermal systems and their dark ecosystems in the Indian Ocean
and the southern Atlantic Ocean. The genetic connectivity of the species will also be assessed
for the demarcation of potential offshore MPAs. We will also characterize the structure of the
southern part of the Mascarene Plateau and the structure and geological history of the Rodrigues
Ridge and investigate the historical climate variability of the region.
(2) Observational study of physical and biogeochemical variabilities in the Indian and Southern
Oceans (L14-31, Talley et al.). The scientific objectives of this theme are to understand
climate-relevant patterns in carbon uptake, upwelling and mixing structure and net community
production in the Indian Ocean and Indian sector of the Southern Ocean.
(3) Volatiles in the Earth and dynamic Cretaceous (L14-49: Seama et al.; L14-35: Dyment et al.).
The scientific objectives of this theme are to clarify heterogeneous volatile content and
migration in the mantle and geomagnetic history in the crust of the Indian Ocean and to estimate
the impacts on the evolution of Indian Ocean.
(4) Hypoxia and sediment biogochemistry of the Bay of Bengal: Benthic ecology and process
studies across contrasting margins (L14-59: Cowie et al.). The scientific objective of this theme
is to characterize the benthic community structures, functions and successions in different
settings of hypoxia in the Bay of Bengal.
(5) Intensive observation cruise for eastern Indian Ocean upwelling research initiative (L14-54:
Matsumoto et al.; L14-14: Ihsan et al.). The scientific objectives of this theme are to
characterize the monsoonal forcing upwelling in the eastern Indian Ocean and to estimate the
impact of upwelling and oxygen-depletion on the nutrient distributions, biogeochemical
processes, productivity and ecosystem dynamics.
(6) Sunda margin geohazards assessment: from passive to active seismological imaging (L14-01:
McHugh et al.; L14-41: Singh et al.; L14-57: Cummins et al.). The scientific objectives of this
theme are to collect high-resolution bottom and sub-bottom geophysical structures along the
Sunda subduction zone and to know the history and the future risk of tunami-earthquake in the
eastern Indian Ocean area.
These components are grouped into three expedition units or initiatives based on the the scientific
objective synergy the observation and survey plans and platforms and the target areas: (1) & (3) can
be conducted together in the in the Central Indian Ridge, Southwestern Indian Ridge, hotspots and
their flanks; (4), (5) & (6) may have geographic affinity in the eastern Indian Ocean and Bay of
Bengal; and (2) require an independent observation strategy for physical oceanography. However,
all the proponents are strongly willing to establishing a comprehensive and interdisciplinary ocean
exploration to challenge major unknowns in the Indian Ocean.
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4. Survey Plan of the cruise(s) (maps required)
The DIO cruise is best implemented by three platform types: (1) surface ships (R/V Yokosuka or
Kairei) with deep-sea vehicles (HOV Shinkai6500 or Kaiko MarkIV); (2) oceanographic ship (R/V
Mirai) with a full array of mooring, Argo buoy and oceanographic and atmospheric observation
tools; and (3) a new JAMSTEC ship capable of both operations. Effectively to use these different
platforms and quite long round-trip tracks of research ships from Japan to various sites in the Indian
Ocean, three years of expedition plan will be required. Although the feasibility and the detail
planning of each of the expeditions will be discussed and optimized among the proponents of DIO
cruise and with the JAMSTEC ship operation committees and department, we provide here a brief
survey plan of the cruise to cover all the scientific objectives and target areas (Figure 1).
In the first year (probably in 2016): R/V Yokosuka or Kairei with HOV Shinkai6500 or ROV
Kaiko MarkIV will first visit the Andaman Sea to conduct the seafloor observation for
hydrothermal systems (8 days on sites and travels tentatively counted) and then will visit the Bay of
Bengal (including the Lombok Basin) for seismogenic zone research and hypoxia ecosystem
research (25 days) under the international framework as shown by yellow lines in Figure 1. Next,
parts of the researches for the Indian Ocean mantle heterogeneity and the CIR deep-sea
hydrothermal vents and ecosystems will be conducted by multidisciplinary onboard scientists from
India to Mauritius (19 days). Then, parts of the researches for the SWIR deep-sea hydrothermal
vents and ecosystems and the geomagnetic survey in the northern flank of SWIR will be done (24
days) and move to the western Australia. Finally, parts of the oceanographic observations of
upwelling in the EIO and the geophysical surveys in the southern parts of the Sunda Trench will be
conducted before returning to Japan (24 days). The several parts of this first year cruise may
contain the themes already approved themes by JAMSTEC (e.g., the CIR and SWIR hydrothermal
vents and ecosystems research).
In the second year: Two platforms will be operated for two legs. Leg 1 using R/V Kairei and ROV
Kaiko MarkIV will visit the Indian Ocean but start with the geophysical survey for the seismogenic
zones of the Sunda subduction zone as shown by purple lines in Figure 1 (15 days). Next, parts of
the researches for the Indian Ocean mantle heterogeneity and the CIR deep-sea hydrothermal vents
and ecosystems will be conducted by multidisciplinary onboard scientists from Indonesia to
Mauritius, including recovery of instruments deployed in the first year (20 days). Finally, parts of
the oceanographic observations of upwelling in the EIO and the geophysical surveys in the Sunda
Trench will be conducted before going back to Japan (15 days). Leg 2 using R/V Mirai will conduct
the oceanographic observation along E80˚ from Kerguelen to Sri Lanka (40 days) and then will take
in charge of geophysical surveys in the northern parts of the Sunda Trench (10 days).
In the third year: JAMSTEC new ship will finalize the DIO cruise. First, the expedition will be
conducted for the oceanographic observation along ˚ E57
from Mauritius t
o the off coast of
Antarctic (45 days), and then the geomagnetic survey in the southern flank of SWIR and the
seafloor observation of the SWIR hydrothermal vents and ecosystems will be done (25 days) to
move to the South Africa. In the way back to Japan, parts of the oceanographic observations of
upwelling in the EIO and the geophysical surveys in the Sunda Trench will be conducted (30 days).
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5. Relevance to other scientific projects in Japan and/or abroad
The DIO cruise is primarily based on the JAMSTEC Mid-term program and the JAMSTEC COE
leadership of international ocean exploration. On the other hand, this cruise will represent the
significant JAMSTEC’s and Japanese contribution to 2nd International Indian Ocean Expedition
(IIOE 2) developed by the Intergovernmental Oceanographic Commission (IOC) and the Scientific
Committee on Oceanic Research (SCOR) of UNESCO to celebrate the 50th anniversary of
International Indian Ocean Experiment. In addition, this cruise will greatly contribute many other
international oceanographic, earth science and marine biological programs such as XXX,
InterRidge (e.g., Circum-Antarctic Ridges WG), IODP and XXXX.
6. Remarks
Figure 1. A map showing a survey plan of the DIO cruise to cover all the scientific objectives and target
areas. Yellow lines, circles and boxes indicate the proposed survey plan in the first year for the expedition
with R/V Yokosuka or Kairei with HOV Shinkai6500 or ROV Kaiko MarkIV. Purple lines, circles and
boxes indicate the proposed survey plan in the second year for the expedition with R/V Kairei with ROV
Kaiko MarkIV and grey lines show the proposed survey plan in the second year for the expedition with R/V
Mirai. White lines, circles and boxes are the proposed survey plan in the third year for the expedition with
JAMSTEC new ship.
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Appendix
Maps in each of the pre-proposals that are finally merged into the DIO cruise.
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