Global Distribution of Hydrothermal Activity Working Group

Chair: Chris R. German

Working Group Members:
USA - Ed Baker
USA - Y. John Chen
UK - Don Cowan
Japan - Toshitaka Gao Gamo
Spain - Eulália Grácia
Germany - Peter Halbach
New Zealand - Gary Massoth
Korea - Dr. Sang-Mook Lee
France - Joël Radford Knoery
USA - Anna-Louise Reysenbach
USA - Dan Scheirer
Canada - Steve D. Scott
France - Kevin G. Speer
USA - Carol A. Stein
USA - Cindy Lee Van Dover
Canada - Verena Tunnicliffe

This working group was active between 1995 and 2001 and had the objective to target areas of the global MOR which are unexplored for hydrothermal activity and coordinate international collaboration to explore them.

2008 - Update on Hydrothermal Vents Database

- The Global Vents Database is currently being updated. To access the old database, click here.

2002 - Global Distribution of Hydrothermal Activity -Update

Reprinted from InterRidge News 11.1 (April. 2002)

This is the first update for two years from this working group, first established in late 1997. There is a reason for the lack of an annual update last year – I was at sea for 70 days in the Indian Ocean helping identify new sites of venting long the Central Indian Ridge and wasn't around to co-ordinate our Working Group's input!!!

InterRidge Theoretical Institute
The first item to bring to your attention in this issue is the imminent demise of the Working Group in 2002. This is in keeping with InterRidge directives on WGs amd their lifetimes – but fear not! We shall be bowing out not with a whimper, but a bang. Specifically, joint with the now-defunct 4-D architecture working group, we shall be co-hosting the first ever InterRidge Theoretical Institute to be held in Pavia, Italy, September 9-13, 2002: "Thermal Structure of the Ocean Crust and Dynamics of Hydrothermal Circulation". The meeting will comprise a 2-day shortcourse - with invited keynote papers plus ample time for discussions and contributed poster presentations - followed by a field-trip to local hydrothermally altered ophiolites and finishing with a 2 day workshop identifying future directions for coordinated InterRidge research. From this WG's perspective, a clear objective will be to improve our understanding of the geological controls of seafloor hydrothermal venting.

Global Distribution of Hydrothermal Activity
It has always been the objective that ANY InterRidge Working Group should be able to make a significant contribution to it's chosen area of focus within the space of ca.5 years. I am pleased to report that ours has been no exception.

Hydrothermal Exploration
Highlights of field programmes since early 2000 have included discovery of new hydrothermal fields along three separate sections of ultra-slow spreading ridge-crest –

1) the Atlantic portion of the SWIR (to be reported by Bach et al. at the InterRidge SWIR workshop in April 2002 – but look out, too, for the paper in G^3 any week now!);
2) the Knipovich Ridge (see, e.g., Tamaki, Cherkashov et al. (IR News 10.1 pp 48-51, 2001); Connelly & German. EOS Trans AGU 83, OS205-206, 2002);
3) most recently, the exciting discovery of abundant hydrothermal signals along the Gakkel Ridge in the Arctic Ocean (see, e.g., Edmonds et al., EOS Trans AGU 82, F647, 2001). In parallel, a UK cruise to the southern Mid-Atlantic Ridge in late 2001 identified clear suspended particulate and dissolved Mn anomalies at a range of sites between 2 and 14 degrees South (C.R. German, unpubl. data) while there have already been wide-ranging reports of the discoveries of first sites of venting in the Indian Ocean during 2000-2001 (Hashimoto et al, InterRidge News 10 (1) pp. 21-22; Van Dover et al., Science 294, 818-821, 2001). In concert, this makes for at least one vent-site now known to exist in every major ocean basin, worldwide, as well as clear demonstration that hydrothermal activity occurs in abundance along even the slowest spreading ridges as well as along the fast and medium-fast.

Global Vents Data-Base, On-Line
Another important achievement of the WG, early on, was the establishment of a readily-updated electronic data-base of every known hydrothermal field – whether visited and sampled on the seabed or just identified from water column anomalies. This database is down at present (July 2007), hopefully to be revived soon. If you would the data in this database as an excel file, please email the coordinator.

Vent Biogeography
Finally, as well as the IRTI leaving the geological aspects of this Working Group in good order (we have also had a very favourable initial response from AGU about publishing a Geophysical Monograph arising from the proceedings) the biogeographic aspects of our work have also progressed well and will be left in good health as the Working Group itself is wound up. WG member Cindy van Dover recently published an invited review article in Science (together with WG co-members Kevin Speer & Chris German, among others): "Evolution and biogeography of deep-sea vent and seep invertebrates" Science 295, 1253-1257. That paper took the opportunity to identify a range of key targets for future investigation, selecting specific regions of the mid-ocean ridge-crest where discovery and biological characterisation of new vent-sites would be of particular benefit. Faster than the current InterRidge WG can disband, therefore, I am pleased to report the establishment of a new related initiative supported by the Sloan Foundation as part of the Census of Marine Life programme. From Summer 2002, Profs. Paul Tyler and Chris German at SOC, UK, will co-host the international pilot office for a new programme, ChEss (Chemosynthetic Ecosystem Studies) dedicated to designing and initiating surveys of life in vent and seep communities on the ocean floor. Funding is for three years, in the first instance; contact Paul Tyler for details.

2000 - Global Distribution of Hydrothermal Activity - Update

Reprinted from InterRidge News 9.1 (April 2000) by Chris German, Chair

There have been a number of areas of activity within the Working Group's organisation in the past few months which affect all of a) Working Group Membership; b) Effectiveness in communication; c) Continuing exploration of the global mid-ocean ridge crest.

a) New Members of the Working Group
Following recommendations from the InterRidge Steering Committee we have continued to expand the membership of our Working Group, expanding both scientific expertise and geographic representation. To that end we have been pleased to welcome two experts in the field of microbiology to the working group: Prof. Anna-Louise Reysenbach (University of Portland, Oregon, USA) and Dr. Don Cowan (University College London, UK). In addition, we are pleased to welcome Dr Gary Massoth of the Institute of Geological and Nuclear Sciences, New Zealand (Gary was formerly part of the highly successful NOAA-PMEL Vents programme in Seattle, USA).

b) Launch of the New Global Vents Data-Base
Second, with the launch of the new InterRidge Web-Site as a whole, comes an upgraded facility from the "Global Distributions" Working Group. This was an idea stimulated by the Spring 1999 meeting of our Working Group at the European Geophysical Society meeting in Den Haag. It has now reached fruition thanks to the careful efforts of past and present InterRidge Co-ordinators, Cara Wilson and Agnieszka Adamczewska. The original database was largely compiled by Mark Hannington. The idea of this data-base is that it should become the international standard for all known sites of submarine hydrothermal activity which can be updated simply by submitting an electronic message to the InterRidge Office.

The Vents Data-base comprises a searchable text-based compilation of 208 separate entries together with a global summary map which identifies and differentiates between all of:
- Known sites of present-day activity
- Known sites of inactive venting
- Areas with hydrothermal sediments
- Unconfirmed Areas (plume signals reported, but no vents yet found)
The long-term plan is that a simple click on the summary map will lead you straight to the relevant data-base entry (but give us time!). In the interim, the text database can already be searched by any of its fields which are: Name, Latitude, Longitude, Region, Spreading Rate, Activity etc, etc, etc. Each listed area includes some basic key-facts such as x-y-z (Lat.-Long-Depth) coordinates, nature of venting present, basic biological description and citation of first paper (peer-reviewed wherever possible) to discuss the location of the site. If you now of any other sites, or believe a more accurate description of a site is already listed then suggested corrections to the data-base are only a click away. We'll look forward to receiving a healthy and steady flow of information to this site so that we can maintain the best hydrothermal data base that we can all benefit from, worldwide.

c) Recent Scientific Highlights
Two recent areas of exploration for new sites of hydrothermal activity have been along the East Scotia Ridge (see report by Roy Livermore et al., InterRidge News 8.1) and the Havre Trough Back-Arc Basin (see report by De Ronde et al., InterRidge News 8.2). In addition, in 1999 KORDI (S.Korea) conducted a 7-day cruise to the eastern Manus Basin, including the PACMANUS area (to be visited by ODP Leg 193, later this year) and a search for a new hydrothermal field in the northern Pual Ridge using underwater camera. The work consisted of shipboard geophysics, hydrocasts, dredging, piston-coring and deeptow camera work.

d) Forthcoming Cruises
In the 2000-2001 time-frame two new areas of exploration and detailed study are currently receiving internationally-coordinated attention. The first area of interest is within the Arctic Basin. Dr Rolf Pedersen (U.Bergen, Norway) is currently leading a five-year Norwegian programme to study the Arctic Ridges which is planned to include a component of hydrothermal exploration. The same is the case for a joint cruise between InterRidge Japan and Russian Colleagues in September 2000 aboard the RV Logatchev. Finally, in Summer 2001, a seventy-day bi-lateral two-ship (Polarstern, Healy) research expedition is proposed between the USA and Germany to investigate the western Gakkel ridge.

The second area of interest in the immediate future is in the Central Indian Ocean. In early 2001 Dr Cindy Van Dover will lead a US expedition involving all of the DSL-120 sidescan and Argo and JASON vehicles to investigate hydrothermal activity close to the Rodriguez Triple Junction. An InterRidge Japan cruise (PI J.Hashimoto, JAMSTEC) involving the Kairei, and the ROV Kaiko is also proposed for the same portion of the Indian Ocean in Aug-Sept 2000 and UK scientists at the Southampton Oceanography Centre have recently submitted a proposal to continue hydrothermal exploration north along the Central Indian Ridge away from the Rodriguez Triple Junction and toward the Rodriguez Hot-Spot - watch this space!

In addition to the two focussed areas of research listed above, in March-April 2000 there will be a US (Fornari, Embley, Tolstoy et al.) "response" cruise to the eastern Equatorial Pacific spreading centers investigating the ridge axis in areas where seismic events - thought to arise from active volcanism - have been recorded by NOAA's moored acoustic hydrophone array over the past few years. The study will focus on an area that has received no prior detailed study and will "interpolate" across some reasonably large gaps between previous study areas of the NEPR, Galapagos and SEPR. The cruise will involve near-bottom sonar and visual imaging, rock dredges, bio-hauls, hydrocasts - and MAPRs attached to just about everything!

In late May 2000, KORDI will conduct a fresh hydrothermal cruise to the Woodlark Basin, in the Solomon Is. The Woodlark Basin has been geophysically mapped by the scientists at University of Hawaii and other institutions, but no systematic seafloor rock sampling has been con-ducted along this ridge axis to date. The goal is to take dredge samples systematically along the spreading axis together with a series of CTD-profiling measurements and, where appropriate, underwater camera runs to seek out new active vent-fields.

1999 - Global Distribution of Hydrothermal Activity - Update

Reprinted from InterRidge News 8.1 (March. 1999), by Chris German, Chair

This working group was first established in late 1997 under a working title Global Partitioning of Hydrothermal Activity with an intention to continue in the vein of what is unique about InterRidge - namely to help foster research which can only be achieved through international communication and coordination.

During discussions at both the InterRidge Steering Committee meeting in September 1998 and an initial meeting of Working Group members in San Francisco in December 1998 it was decided to make explicit the particular focus of the group by renaming it as indicated above. This name reflects our primary objective: to seek out and investigate new sites of axial hydrothermal venting along previously un-studied sections of the global mid-ocean ridge crest.

A particular objective, in this regard, is to further our understanding of vent biogeography. To a first approximation, the fauna of the Juan de Fuca Ridge/Northern East Pacific Rise (JdF/NEPR) vent-sites are quite distinct from those of the northern Mid-Atlantic Ridge (MAR), but no active vent-sites have yet been visited/observed by manned submersible or ROV anywhere between the S. Pacific Ocean and the low-latitude N. Atlantic. Vast tracts of the global mid-ocean ridge crest system remains unstudied by the hydrothermal research community. While the principal objective of our research, as stated above, has a biological theme, it is also most certainly the case that increasing our coverage of studied hydrothermal areas will also throw new light on the chemical and physical nature of hydrothermal circulation in different geological regimes. As we continue to seek out new sites of venting, therefore, it is to be expected that we will continue to make important new, and as yet unanticipated, discoveries across the disciplines.

As a first stage to implementation of the working group's objectives, and recognising the key role that vent biogeography has to play, a first course of action is to attract additional biological scientists including micro-biologists from across the international community to help steer the scientific agenda for the working group. If you would be interested in making that contribution, please contact me.

Our next step will be to identify key areas where maximum scientific returns can be expected. To that end, an important start has already been made along the Indian Ocean Ridges where hydrothermal plumes and seafloor deposits have recently been reported from all of the Central, SE and SW Indian Ridges. Various proposals from across the international community are now underway and/or awaiting shiptime to follow up with seafloor observations of these ridge crests. Therein lies the most compelling challenge of this working group: many of the sections of ridge-crest most pertinent to our study are remote; they require complex logisitical arrangements to reach them; and the difficulties of working in high-latitude environments should not be underestimated.

To maximise efficiency in an internationally coordinated way, therefore, we have identified the following course of action:
# To expand membership of the WG to accommodate a stronger biological influence.
# To identify key areas of highest priority for biogeographical studies, at the basin scale.
# To identify key ridge sections within those basins where basic underlying geophysical and/or geological data-sets (swath bathymetry, sidescan imaging, petrology) have already been collected - this provides a valuable infrastructure and also allows any new hydrothermal discoveries to be placed within a geological context.
# To encourage and support research applications using suitable ships from across the international community to prospect for hydrothermal activity using water column geochemical survey techniques, with or without other related geological/biological investigations, to pinpoint new sites of hydrothermal venting on the seafloor.
# To publicise the results of any such research activities through InterRidge News to help stimulate new follow-on proposals, which may be at either the international or the national scale, to conduct first seafloor investigations at these positive targets.

Key target areas for future survey work will include: The southern MAR and the Arctic ridge crests. The former is of high priority because it will provide improved continuity for vent biogeography studies between the northern MAR and the Indian Ocean (we assume, here, that first successful dives on an Indian hydrothermal site are now just a matter of time...).

The case for the study of the Arctic ridge crests, north of Iceland, is that this is the section of ridge-crest most remote from the well-characterised JdF/NEPR and underlies the most extreme oceanographic conditions. As such, it can be hypothesised that these ridges will host the most unique vent-biota. Additionally the Gakkel Ridge in the Arctic is the slowest-spreading ridge in the world, making it an important end-member for various mid-ocean ridge processes, as such research on this ridge is the focus of another InterRidge working group (see page 7).

There are a number of other remote sections of ridge crest where evolutionary biological studies could be addressed. These include: deep vent-sites of the Mediterranean Sea, the Cayman Trough, the Andaman Sea, the E. Scotia Ridge, the Brans-field Strait and the Gulf of Aden. Perhaps the most intriguing of these is the Cayman Trough. Here (geologically) recent closing of the Isthmus of Panama may have effected late-stage isolation of the Mid-Cayman Rise from the NEPR/JdF ridge system. As such, it will be of great interest to evaluate the relative similarity (or otherwise) of Mid-Cayman Rise vent-fauna when compared to those of (e.g.) the northern EPR, the adjacent cold-seep fauna of the Gulf of Mexico and the high- temperature vent-fauna of the similar latitude MAR.

In future issues of InterRidge News we will keep you informed of new developments in many of these work-areas including results from completed cruises as well as the confirmed logistics for future expeditions. Similarly, as more gaps become filled in along the global mid-ocean ridge crest, the scientific questions we wish to address will certainly change and our periodically re-focused objectives will also be reported here. As part of this continuously evolving process, the next opportunity to meet amongst members of the WG will be in Europe, in association with the EGS Open Symposium at Den Haag, April 1999.

1998 - Global Distribution of Hydrothermal Activity -Update

Reprinted from InterRidge News 7.1 (April. 1998), by Chris German, Chair

During 1997 it was agreed by the InterRidge steering committee that the "Segment Scale Fluxes" working group should be wound-up. Effectively, it was considered that the water-column components - studying the physics, chemistry and biology of hydrothermal plumes on a segment scale - had been implemented as best as could be achieved through international collaboration through two recent series of cruises to the Mid-Atlantic Ridge at Broken Spur (29°N) and Rainbow (36°N). Simultaneously, in the absence of a volunteer to promote the parallel themes identified by the 1995 InterRidge Workshop on segment-scale fluxes (Elderfield et al., 1996) it was argued that those interests could most satisfactorily be subsumed into the related 4-D architecture working group.

Simultaneously, however, it was recognized that there was advantage to establishing a new InterRidge Working Group dedicated to implementation to some aspect of hydrothermal circulation research. To this end, Cara Wilson and I convened an open discussion meeting at the American Geophysical Union's Fall Meeting in December 1997 to discuss, at "grass-roots" level what the new direction of this new Working Group should be. An important term-of-reference for this meeting, I proposed, should be to return to one of the basic premises of InterRidge, namely to target those areas where international collaboration would be most important and effective. An inverted way of expressing the same principal would be to avoid duplication of what could already be achieved through existing national research programs. Possible avenues for development included:

1. Winding up the segment-scale fluxes working group but starting nothing new.
2. Commencing a working group studying on-axis vs off-axis partitioning of fluxes.
3. Commencing a working group studying global partitioning of venting around the world's ridge-axes.

Whilst the partitioning between on-axis and off-axis venting remains an important area for future research it was considered that this was already a relatively well-coordinated area of research at the international scale due to the activities of both the Ocean Drilling Program (e.g. recent Leg 168) and the International Lithospere Program (new program approved in 1997, coordinated by Earl Davis, USA & Harry Elderfield, UK). Therefore, it was decided, following the December 1997 AGU discussions, to pursue the possibility of developing a new InterRidge Working Group dedicated to developing and coordinating international studies of the partitioning of hydrothermal venting around the world's mid-ocean ridge-crests from very slow to very fast spreading rates. A call for expressions of interest was sent out in late December to the entire InterRidge mailing list (see below) with submissions from interested parties invited by the end of January 1998.

16 responses were received from 5 countries, spanning a range of disciplines and expertise from vent biology to theoretical modeling of heat flow and from ridge dynamics to plume dynamics. During discussions in February with Mathilde Cannat and Cara Wilson at the InterRidge Office and we developed at an initial wish-list of invitees to form the working group. The membership reflects not only the range of interests expressed, but also the international composition of InterRidge. The process of invitations and acceptance is already well underway and, to date, we have received firm acceptance from 14 members from 8 countries (Canada, France, Germany, Japan, Korea, Spain, UK, and USA). A preliminary meeting is being considered for next December, to coincide with the Fall AGU meeting in San Francisco, USA.. The purpose of this meeting - of Working Group Members only - would be to establish/identify/prioritize preliminary areas of interests - with the option of expanding to a full InterRidge Workshop in the future.

Call for Input/Statements of Interest (Dec. 1997)

It is now recognized that hydrothermal circulation is more widely distributed around the world's ridge-crests than had been previously thought. For physicists and geochemists this is of importance when determining global hydrothermal fluxes which, to-date, may only be cosntrained to within an order of magnitude. Additionally, for relatively short residence time chemical species which are not well-mixed throughout the world's oceans, it is important to improve our understanding of how their hydrothermal input is partitioned between the world's deep ocean basins. For marine biologists it is important to understand how different biogeographic provinces have developed as a key to improving our understanding on the nature and rates of evolutionary processes. Also, given the diversity of species, new to science, which have already been found at the various vent-sites discovered so far, it seems clear that we have not yet witnessed the full global biodiversity of these extreme submarine environments.

Following discussions by the InterRidge steering committee and an open InterRidge meeting at the American Geophysical Union's Fall Meeting, on Dec.11 1997, we propose to establish a new InterRidge Working Group aimed at targetting, and coordinating international collaboration in new areas of the global ridge-crest which, to date, remain unexplored for hydrothermal activity. Clearly, it is neither practical, nor desirable, to attempt systematic hydrothermal mapping of the entire global ridge-crest. Rather, we propose to adopt an intelligent approach to targetting new areas for research, informed by both geophysical and geological input (e.g. selecting areas with pre-existing swath bathymetry but also identifying key tectonic provinces or petrologic domains) as well as being steered by vent biogeographers' input as to key areas in which discovery of new species might be most informative concerning global distributions of vent-specific species through time.

We already have a simple and testable model which predicts that frequency of venting should be directly related to heat-flux/spreading-rate. However, it is already clear that this model needs further verification and detailed revision, not only along slow and fast spreading ridges but also in back-arc basin spreading centres. Additionally, the question of how hydrothermal fluxes at a given ridge location are partitioned between vents and more diffuse and cooler fluxes needs further investigation, in a variety of spreading environments. We welcome any further input that individuals may be able to contribute - either because they were unable to attend the open discussion at AGU, or because they have had further time to reflect since that meeting. We seek contributions from suitably experienced geophysicists, petrologists and vent biologists as well as the hydrothermal researchers who, we envisage, will form an integral part of this working group. Please send your contributions to Cara Wilson at the InterRidge Office in Paris before the end of January 1998. Cara and I will compile any additional input received, and, over the timescale, we will invite participation in an opening membership of the WG (approx. 10 people). In keeping with InterRidge objectives, invitations to join the working group will be made to ensure that the group reflects a suitable blend of both interdisciplinary and international expertise. The aim will be to convene a first meeting of the Working Group itself, as early as possible in 1998, to prepare a preliminary project plan for the working group, which it is hoped would be able to identify a series of key target areas for future new research as well as establishing a mechanism for coordinating more efficient add-on hydrothermal upgrades to already funded geophysical and geological cruises.

I shall look forward to hearing from you in the New Year.

Best wishes, Chris

Chris German, SOC
WG Chair