International Ocean Network (ION)

barbara (at) seismo.berkeley.edu, suyehiro (at) jamstec.go.jp, adam (at) coas.oregonstate.edu

*Berkeley Seismological Laboratory, Berkeley, CA, USA. **Deep Sea Research Department, JAMSTEC, Tokyo, Japan. ***College of Oceanic and Atmospheric Sciences, Oregon State University, Corvallis OR, USA.

During the Fifth IRIS (Incorporated Research Institutions for Seismology) Hawaii meeting, an OSN (Ocean Seismic Network) Technical Workshop was held with international participation. At this time, not only future plans were reported, but also experiences of ocean downhole seismic experiments by the Japanese (Japan Sea borehole) and French (Atlantic Ocean borehole and buried) among other seafloor experiments. Quickly, the need was recognized among the participants to form an international group that would help accelerate and coordinate each interested country's efforts to expand the global seismic network into the oceans, which seemed feasible and realistic. Thus, the ION Committee was established in June 1993 and was granted commission status by the IASPEI executive committee.

In January 1995, during the first International ION workshop in Marseille (France), ION's participation was extended to other solid earth disciplines, and in January 2001, during the OHP/ION Symposium in Mt. Fuji (Japan), participation in ION was extended to oceanographic disciplines.

Kiyoshi Suyehiro, Ocean Research Institute, Univ of Tokyo, Japan (Chair) (93-98)

Adam Dziewonski, Dept of Earth and Planetary Sciences, Harvard Univ, U. S. A. (93-)

Barbara Romanowicz, Seismological Lab., U. C. Berkeley, U. S. A. (Secretary, 93-97; Chair, 98-)

1993 August - ION joined with JOI (Joint Oceanographic Institutions, Inc., U. S. A.)/IRIS OSN (Ocean Seismic Network) group produced an OSN/ION Planning Document for distribution among the JOIDES (Joint Oceanographic Institutions for Deep Earth Sampling) community. A sub-committe (R. Stephen, WHOI, chair) was formed to report on the technological merits and demerits of borehole seismological observations and to seek international technical coordination of future borehole experiments.

1994 December - ION committee meeting was held during the Fall AGU together with OSN (Ocean Seismic Network)-US group, to discuss and plan the ION workshop in 1995.

1995 January. - ION workshop sponsored by French, U.S. and, Japanese institutions was held in Marseilles (Jan. 11-13) with more than 80 attendants from 8 countries discussing scientific targets and technical considerations. Wide inter-disciplinary discussions were held. The proceedings of the workshop is available for distribution from national representaives' offices as well as from JOI. During this workshop, the charter of the ION was expanded and also the number of committee members were increased to cover the wide spectrum of scientific disciplines.

Giuseppe Smriglio, Instituto Nazionale Geofisica, Italy (95-01 deceased), then Paolo Favoli, INGV, Italy (01-)

1995 July. - ION held a one-day session (July 5) as an IASPEI led inter-association symposium together with IASPEI, IAGA and IAG on Long-term seafloor observatories and networks. After the session, ION committee met and discussed the future plans relating to borehole observatories, where ocean drilling is required. In view of the fact that the major ION activities currently involve seismology, geomagnetism, and geodesy, it was discussed that ION would seek linkages to IAGA and IAG as well.

1995-1999. - ION has been proactive in promoting the establishment of deep sea floor observatories. Under its umbrella, several pilot experiments have been performed, among them the OSN1, which collected data from seafloor and downhole seismometers at a site 200 km southwest of Hawaii during a 5 months period (02-06/98), and the MOISE experiment, which collected 3 months of data in the summer of 1997, from an ROV deployed site in Monterey Bay (California). In Italy, the GEOSTAR group is developing a multiparameter ocean bottom station currently under testing in the Mediterranean sea, and groups in other european countries, in particular France and the U.K. are also putting efforts into seeking funding to support ocean bottom observatory programs.

1996 May. - European Geophysical Society meeting: ION met on May 8 17:00-19:00. ION session: SE25.

1996 June. - The ION Committee together with R. Stephen and J. Orcutt submitted an ODP proposal titled "Global Siting Plan of Borehole Geophysical Observatories by ION". This proposal included all the ION related ODP proposals and letters of intent and described the ION plans in a global perspective for the benefit of the ODP community.

1997. - As part of an ODP panel structure, Long-Term Observatories Program Planning Group was formed co-chaired by K Becker and K Suyehiro. This PPG liaised with ION and has been an important voice for realizing ION proposals.

1997 Nov. - ION co-sponsored the first OHP international symposium held in Chiba, Japan.

1998 June. - A special issue of Physics of the Earth and Planetary Interiors (vol. 108-2) on "Seafloor Observatories and Geophysical Networks: The present and the future", guest ed. K. Suyehiro and J. P. Montagner, was published as proceedings of 1995 IUGG meeting session.

1998 Dec. Fall AGU ION Symposium (U32B) "Deep Ocean Observations from the Seafloor"

1999 July. IUGG'99 Birmingham. ION Symposium (JWA34):" Long term ocean bottom observatories"

1999. - Two Japan Trench sites drilled during ODP leg 186 and instrumented during leg 191, each with strainmeter, tiltmeter and 2 broadband seismometers.These sites were established as the first ocean downhole crustal deformation observatories. Cabled seafloor broadband seismometer station installed at H20 site, half way between Hawaii and California.

2001 April. - Leg 195 successfully emplaced 2 broadband sensors in the center of the Philippine Sea.

2001 December. - Leg 200 successfully installed a cased, legacy borehole at the H2O cabled observatory site, mid-Pacific.

2002 May.- Leg 203 successfully installed a cased, legacy borehole at the OSN-2/ION Pacific Equatorial Site, for future installation of borehole broadband seismometer, and complementary borehole and seafloor observatory instruments.

2003. ION IODP Proposal submitted by Ralph Stephen on behalf of ION to inform IODP of future proposals to complete global borehole geophysical observatories on the seafloor.

2005. ION ORION RFA Proposal submitted by Ralph Stephen on behalf of ION as part of US NSF ORION Ocean Observatory Program's request for assistance in defining science to be carried out under the heading of global-scale (buoy-based observatory) research.

ION has held a second international workshop in Japan, in January 2001, in conjunction with the OHP (Ocean Hemisphere Project) Symposium.

1) enlarge participation to the oceanographic research community interested in long term ocean observatories

2) following the recommendations outlined during the NRC Workshop held at Cheeca Lodge, Florida 01/09-01/12/00, start developing technical standards and international management organization for the global long-term ocean observatory network.

During this meeting, the ION charter and recommendations were updated to include the larger oceanographic community and two new members were added to the steering committee:

ION welcomes the participation of all individuals interested in promoting international cooperation on long term ocean observatories. Further information can be found on the ION webpage at:

**Figure:** Stars: location of designated land stations of the Federation of Digital Seismic Networks (a subset of existing global digital broadband stations). Squares: location of ION/ODP boreholes. OSN1 and OFP have been discontinued. NERO awaits instrumentation. Circles: sites of scheduled ION/ODP holes. H20 is currently recording data from seafloor broadband sensors.
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Last update: July 13, 2007

History

History of the International Ocean Network