NEPTUNE
Real-Time, Long-Term Ocean and Earth Studies
at the Scale of a Tectonic Plate
1

2

1

3

John Delaney , Alan Chave , G. Ross Heath , Bruce Howe , Patricia Beauchamp

4

1

School of Oceanography, University of Washington, Seattle, WA
2
Woods Hole Oceanographic Institution, Woods Hole, MA
3Applied Physics Laboratory, University of Washington, Seattle, WA
4
Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA

ABSTRACTThe NEPTUNE project will establish a linked
array of undersea observatories on the Juan de Fuca
tectonic plate. The NEPTUNE infrastructure,
consisting of fiber-optic/power cable and junction
boxes, will provide significant amounts of power
and an Internet communications link to sensors andsensor networks on, above, and below the seafloor.
This observatory will provide a new kind ofresearch platform for real-time, long-term, platescale studies in the ocean and earth sciences.
INTRODUCTION
The NEPTUNE project is developing a fiberoptic/power network of distributed sensors on,
above, and below the Juan de Fuca tectonic plate in
the northeast Pacific Ocean (Figure 1a,b).
Scheduled to be operational by 2006, the
NEPTUNE observatory will provide a new kind ofresearch platform for real-time, long-term, platescale studies in the ocean and earth sciences.
The planned 30 experimental nodes for the
NEPTUNE system could be distributed over a
volume extending from the air–sea interface to thebottom of the oceanic crust and will cover an areathat includes the entire Juan de Fuca Plate, its
margins, and beyond. These in situ n o d a lobservatories will be spaced approximately 100 kmapart on the network. Each will have a significant
footprint of instruments bounding a volume ofocean space. These arrays will permit remoteinteraction with physical, chemical, and biologicalphenomena operating across multiple scales ofspace and time. Observatories in key areas ofinterest will be spatially extensive, covering areas
up to 50 km in diameter. It will be possible toextend NEPTUNE’s cable-defined footprint
through the use of moored and relocatable buoys.
The electro-optical cable will provide
significant power and high-bandwidth
telecommunication capabilities to this array of
instruments and sensors, permitting real-time datatransmission and remote two-way commandcontrol of instruments and robotic undersea
vehicles. Data will flow in real time fromNEPTUNE’s in situ facility to land-based scientists,
educators, decision makers, and learners of all ages
(Figure 2).
NEPTUNE offers a new means of observing
and understanding our planet. It will foster a more
integrated era of research and education in theocean and earth sciences and may also serve as aunique testbed for sensor and robotic systems
designed to explore other oceans in the solar
system.
PARADIGM SHIFT IN THE OCEAN SCIENCES
Traditional expeditionary science has
characterized some portion of an ocean or planet
within the constraints of data collection from a shipor spacecraft. Such time-limited visits are
inadequate to fully evaluate the suite of models andtestable hypotheses that have grown out of this
exploratory work.
Ocean scientists now stand on the threshold of ascientific revolution, a paradigm shift madepossible by advances in computational
sophistication, communication and power
technologies, robotic systems, and sensor design.
The ability to enter, sense, and interact with thetotal ocean environment is within our grasp. It istime to expand beyond short-term expeditions using
research vessels; it is time to move toward a

Figure 1 (a) NEPTUNE cable system map. NEPTUNE will provide power and communications bandwidth
via fiber-optic/power cable to junction boxes (nodes) on the Juan de Fuca Plate and surrounding areas. By
connecting sensor networks to the nodes, with extensions onshore and offshore into the interior, scientists
will for the first time have the capability to study a host of interrelated processes with high spatial andtemporal resolution over long periods of time. (b) A generic NEPTUNE observatory network, draped over
Axial Volcano and based on the NOAA/PMEL New Millenium Observatory.

Figure 2. Land-based scientists and the public are linked in real time and interactively with sensors, sensor
networks, and various mobile sensor platforms in, on, and above the seafloor. NEPTUNE’s fiberoptic/power cable and associated technology provide the enabling network infrastructure.

long-term presence on, above, and below a sectionof seafloor as large as a tectonic plate.
NEPTUNE’s plate-scale observatory concept isbased on the following premises:•
Many globally significant planetaryphenomena, involving both oceanographic andsolid earth processes, operate at or below the scaleof a tectonic plate.
•Thorough four-dimensional examinationof at least one plate/mesoscale system will generate
major new insights into all such systems.
•
Understanding the interactions among the
myriad processes operative at such scales will
require decadal commitment to the studies.
A recent U.S. National Research Council report(NRC, 2000) concluded that “Seafloor
observatories present a promising, and in somecases essential, new approach for advancing basic
research in the oceans.” Based on this report’s
recommendations, the National Science Foundation
has proceeded with a new program to support longterm research observations and interactive
experiments from the sea surface to the seafloor
and beneath. NEPTUNE anticipates participating as

the regional, tectonic-plate-scale component of thisOcean Observatories Initiative.
Observatories such as NEPTUNE will create
opportunities to address such compelling
intellectual and societal themes as the search for life
within and beyond earth, anticipation of crippling
natural hazards, improved management of marine
resources, anthropogenic influences on ocean andclimate systems, and a deeper understanding of
habitat complexity.
INNER SPACE/OUTER SPACE
The spectrum of scientific studies currently
envisioned for the NEPTUNE facility covers abroad range. One major opportunity arises fromrecent evidence that submarine volcanoes support a
substantial, unexplored high-temperature microbial
biosphere sustained by volatile fluxes from theearth’s interior. This insight implies that seafloorhydrothermal vent fields may be the “tips oficebergs” in total biomass supported by active
submarine hydrothermal systems. A significant
microbial biosphere apparently thrives within thebrittle outer shell of the volcanically active
submarine portions of earth.

Similar submarine volcanic systems may exist
on other solar bodies, such as Europa, the second
moon of Jupiter. The new field of microbial
volcanic ecology is, therefore, doubly powerful. By
designing innovative strategies to explore therelationships between volcanoes and the life they
support here on earth, we gain not only essential
knowledge about newly discovered processes andlife forms on our own planet, but also critical new
insights into how we might explore for signs of lifeon other solar bodies. NEPTUNE will allow
intimate real-time access to the vigorous
geophysical and geochemical processes that sustain
this sub-seafloor volcanic biosphere.
NEPTUNE may also serve as a unique testbed
for sensor and robotic systems designed to explore
other oceans in the solar system. Indeed, we canregard NEPTUNE as an inward-looking Hubble
telescope, vastly enhancing the potential for
discovery by allowing unprecedented fourdimensional imagery of planetary processes notentirely restricted to earth: by looking inward,
focusing on integrated, scientific experimentationin remote or hostile environments on our own
planet, we will also be looking outward.
THE NEPTUNE STUDY AREA
To attract the broadest possible user base to thisfull-service oceanographic research platform and tominimize cost, we sought a study area that had asmall footprint but encompassed myriad importantearth and ocean processes. The Juan de Fuca plate
was chosen for its representative spectrum of
globally occurring earth-ocean processes andbecause it is in an ideal location close to major
ports in British Columbia, Washington, andOregon. The Plate is small and entirely submarine,
and we propose treating the entire system as an
ocean-earth laboratory (Delaney et al., 2000).
THE FEASIBILITY STUDY
One of NEPTUNE’s important early efforts wascompletion of a feasibility study in June 2000
(NEPTUNE Phase 1 Partners, 2000). The study was
funded by the National Oceanographic Partnership
Program and by the four NEPTUNE Phase 1
partners (University of Washington, Woods Hole
Oceanographic Institution, the California Instituteof Technology’s Jet Propulsion Laboratory, andNOAA’s Pacific Marine Environmental
L a b o r a t o r y ). Many other institutions andindividuals contributed generous time and effort tothe feasibility study. Since completion of the study,
two more partners have joined the project:
Canada’s Institute for Pacific Ocean Science andTechnology (IPOST) and the Monterey Bay
Aquarium Research Institute (MBARI).
The feasibility study, which is posted on the
NEPTUNE web site (www.neptune.washington.edu),
concluded that 1) there are strong intellectual andsocietal drivers for implementing NEPTUNE,
2) NEPTUNE is feasible from a technological pointof view, and 3) within the context of what
NEPTUNE brings to the earth, ocean, and planetarysciences, the system cost is reasonable.
SCIENTIFIC OPPORTUNITIES/SOCIETAL BENEFITS
We will be able to address a host of scientificopportunities and societal challenges with thecapabilities envisioned for NEPTUNE. Indeed, theultimate measure of success of any scientificfacility is the innovative character and quality ofthe scientific research and public education that are
enabled.
The ad hoc science working groups listed below
were convened to hold brainstorming sessions to
identify research opportunities that NEPTUNE
could enable and to develop preliminary examplesof science experiments.
•
•
•
•
•
•
•

Cross-margin particulate fluxes
Seismology and geodynamics
Seafloor hydrogeology andbiogeochemistry
Ridge-crest processes, subduction zone
processes (fluid venting and gas hydrates),
Deep-sea ecology
Water-column processes, andFisheries and marine mammals.

The working groups addressed the scientificviability of large, long-term group or community
studies and of shorter-term individual investigator
experiments and observations. The white papers
produced by these working groups are posted on
the NEPTUNE web site. Listed below are some ofthe scientific opportunities and societal benefits thatwill be engendered by NEPTUNE.
For the first time, using NEPTUNE,
earthquake and deformation patterns associatedwith the creation, aging, and destruction of oceanic
plates can be examined in a continuous, integrated
fashion for decades. The NEPTUNE study area
includes all major types of oceanic plateboundaries, including the Cascadia subduction zone
(Fluck et al., 1997; Wang et al., 1997). A seafloor
seismic network will capture the earliest signals
from great subduction zone earthquakes and cancontribute critical information to tsunami andground-shaking warning systems. NEPTUNE isvery complementary to U.S. and Canadian
initiatives to enhance land-based observations.
• Ridge-crest volcanism is intimately related to
the formation of metal deposits, modulation ofseawater compositions, local heating of theoverlying ocean, and support of a microbial
biosphere. NEPTUNE’s capabilities will help
establish the specific nature of links and variations
between geological, physical, chemical, andbiological processes at active mid-ocean ridges(Delaney et al., 1998). A crucial use of NEPTUNE
will be rapid response to eruptions of submarine
volcanoes to sample the exotic microbiologicalmaterials released there. Enzymes extracted fromdiverse microbial communities supported byextreme conditions within the ocean and underlying
crust are and will be sources of bioactive materials
for powerful industrial applications. The ability to
track and sample otherwise undetected eruptive
events will give us new access to such compounds.
• Despite the vigor of ridge-crest activity, it
constitutes less than 10% of the total global flux ofheat and chemicals from the earth’s interior. Ridge
flanks and mid-plate portions of our planet
represent the zones of major heat and chemicalt r a n s f e r from the earth’s interior to thehydrosphere and biosphere. Instrumented boreholes
within the oceanic crust can serve as laboratories
for studying the interdependence of tectonics, fluid
and thermal flows, and biological activity (Davis etal., 1995). Early evidence indicates that these
relationships are at least partially forced by tides,
but the ramifications are not clear. Intriguing new
data suggest that plate activities may be moreinterconnected than previously suspected.
• Studies of the volatile fluxes expelled along a
subduction zone will allow cross-correlation withmajor and minor earthquake activity, thus giving
crucial information about potentially major, nonsteady-state carbon movements. The role ofsubduction gases and methane hydrates in the
dynamics of the continental slope is virtually
unknown. The classic study site for fluid venting
and gas-hydrate formation and breakdown islocated within the NEPTUNE study area (Suess etal., 1999). Global interest in hydrates reflects theirrole as a vast potential energy resource and asignificant source of greenhouse gases.
Documentation of the formation and accumulation
rates of gas hydrates, as well as metal deposits, will
provide new insights into the search for scarce
resources.
• Migration of fish stocks and marine
mammals along and across the continental shelf
can be quantitatively tracked using innovative
acoustic techniques (McDonald and Fox, 1999).

Tying this to small- and large-scale oceanography
and the regional carbon budget will be a worthy
challenge.
• A fully instrumented suite of water-column
moorings will allow continuous four-dimensional
real-time assessment of the physical, chemical, andbiological interactions in a zone of divergence andin nearshore upwelling processes. Collecting
model-guided, continuous, long-term data series
will improve current models of the oceanic
processes that occur in the NEPTUNE study area
and could fundamentally re-orient biologicalapproaches to ocean science (e.g., Haidvogel et al.,2000 and Glenn et al., 2000). NEPTUNE will also
provide the capability to conduct uniquequantitative assessments of certain portions of the
carbon cycle.
• Sediment transport along and across thecontinental shelf and into the deep ocean can bequantified as a function of the processes that drive
such systems. Large fluxes of sediment laden withcarbon and anthropogenic chemicals cross thenortheast Pacific continental shelf to the adjacentdeep-sea floor in a highly episodic fashion during
major storms (Nittrouer and Wright, 1994). The
mechanisms, however, are largely unknown.
NEPTUNE’s capabilities will permit measuring,
sampling, and experimentation during these
episodic events. A more complete understanding ofwater-column physics, chemistry, and biology will
permit addressing the links between primary
productivity, fisheries, marine mammal migration,and deep-sea ecology.
• The deep sea represents two-thirds of ourplanet yet is virtually unexplored in terms of
biocomplexity. The NEPTUNE network will
provide the capability to develop a functional
understanding of the ecology of deep-sea biota,
only a small percentage of which have beensampled or identified (Smith et al., 1997).
ENGINEERING OVERVIEW ANDINFRASTRUCTURE
Moored Buoys vs. Cable. There are two distinct
approaches to providing power and communications
to a distributed set of seafloor science nodes: 1) a
distributed set of buoys, each linked to a seafloor
science node, and 2) a seafloor fiber-optic
telecommunications cable connecting a distributed
set of science nodes to one or more shore stations.
In the first case, the moored surface buoys supply
power to the seafloor instruments and provide asatellite data link to land. In the second case, theseafloor fiber-optic telecommunications cable links
the science nodes to one or more shore stations.
Selecting the most appropriate approach depends

on the amount of power needed for seafloor nodes
and science instruments, on the maximum
anticipated data rate over the lifetime of
NEPTUNE, and on cost.
Power and data-rate issues argue strongly
against the use of buoy technology for the core
portions of the NEPTUNE array. The use of buoys
would place significant limitations on NEPTUNE
experiments because the power requirement for
NEPTUNE exceeds the several hundred watts that
could be provided by buoys. Similarly, the required
data rate capacity for a NEPTUNE science node
exceeds that which a satellite link can service by
several orders of magnitude. In addition, therequired technological developments andcommercial uncertainty surrounding available
satellite systems further weakens the case for theiruse.
Underwater fiber-optic telecommunications
cable technology, however, is highly advanced andcommercially available. It is capable of handlingthe higher data rates needed for NEPTUNE andproviding the needed levels of power to theseafloor. Using a non-standard approach for power
delivery, it is feasible to send many tens ofkilowatts to the seafloor. For these reasons, wehave selected the cable approach for NEPTUNE.
Observatory requirements. NEPTUNE’s infrastructure must meet the following requirements ofthe scientific program:• Bandwidth capable of supporting HDTV
and acoustic tomographic studies at manynodes
• Power to operate autonomous underwater
vehicles (AUVs) and bottom rovers• Very accurate timing signals to support
dense seismometer arrays• Real-time information on the status of
instruments• Real-time ability to change measurement
parameters and download data
• Reliable time series measurements, and• User-friendly information management
system.
To meet these requirements, NEPTUNE isplanning at least two shore stations: one inVictoria, Canada, which will include a major
visitors’ center, and one in the U.S., most likely in
Nedonna Beach, Oregon. Shore stations will
provide power and communications to the cable, as
well as controlling and managing the overallsystem. The main cable, which will be standard,commercial-off-the-shelf cable from the submarine
telecommunications industry, will be buried out toa water depth of about 2000m to protect it fromfishing trawls and will carry power andcommunications to the seafloor nodes, to which
instruments will be interfaced.
We have selected a mesh network topology forthe power and communications systems to meetcapacity requirements and to maximize reliability
and flexibility (Chave et al., 2001). The basic
trade-offs in the power system design can be madeeasily and mean using a DC "parallel" approachwith self-regulating power supplies, which is unlike
conventional submarine telecommunications
systems. Our power system designs indicate thatmuch as 100 kW overall can be delivered for theentire 30-node scenario. The basic power needs canbe met with 2 – 10 kW per node. Major power
consumers include instruments that require motion(AUVs, pumps), heat transfer (freezers to preserve
specimens, heaters for polymerase chain reactions
used in DNA work, heaters for clathrate studies),
light (video), and “hotel” electronics. The major
consumers of communications bandwidth are video
and high-frequency acoustics; significant fractionsof a gigabit per second are required at a node, withorder 10 Gb/s required overall.
Gigabit Ethernet, the high-speed version of awidely used data networking technology, has been
selected as the backbone c o m m u n i c a t i o n stechnology that will meet NEPTUNE’s
requirements. This dependable and affordable
system is based on data networking technology
widely used to connect the Internet to laboratories,classrooms, and homes around the world. The
primary development effort will be in theengineering integration of available, commercialoff-the-shelf components. Innovations will optimize
nonstandard approaches to power andcommunications to meet NEPTUNE’s special
needs.
The Canadian National Research Council’s
Herzberg Institute of Astrophysics is leading the
NEPTUNE data management and archiving
effort. This Institute, located in Victoria, British
Columbia, is responsible for the Hubble Space
Telescope archive in Canada and is one of the key
institutions in the Gemini project. The NEPTUNE
data management and archive facility will be
designed to allow users efficient and seamless
access to NEPTUNE data. The approach is basedon distributed archiving of selected data combinedwith robust and reliable data access and mining
tools. The facility will provide the scientificcommunity, educators, and the general public withon-line access to all NEPTUNE scientific data toensure maximum use of those data and to guaranteethat data sets are preserved for use by future
generations.

Although significant research and development
are required in the realm of robust, versatile
chemical and biological sensors, a suite of existing
oceanographic and geophysical instruments isavailable today for straightforward adaptation to the
NEPTUNE infrastructure. For these reasons,excellent scientific opportunities and outreachcapabilities can be realized as soon as the system isin place. With time, growing sophistication of new
sensors and evolving experimental strategies will
strengthen NEPTUNE’s contributions tooceanography.
EDUCATION AND OUTEACHNEPTUNE’s Internet technology offers great
educational potential. It can provide a wide range of
new opportunities to explore and investigate thedynamics of the marine world using real-time data
flow to classrooms and living rooms coupled with
cutting-edge visualization techniques.
The first workshop on NEPTUNE’s educationand outreach effort was held in November 2000.
Sixty-five participants, including science teachers,
curricula developers, educators at science centers
and aquariums, and scientists, spent two days
together brainstorming ideas on the best use of
NEPTUNE’s real-time data capabilities in formal
and informal science education. A report from thismeeting is posted at www.neptune.washington.edu.
INTERNATIONAL PARTICIPATIONNEPTUNE is an international program. The
study area spans the territory and exclusive
economic zones of the U.S. and Canada.
Approximately one-third of the Juan de Fuca Platelies within Canadian waters and two-thirds within
U.S. or international waters. In addition to our
NEPTUNE Canada partner, scientists at GEOMAR
Research Center for Marine Geosciences in Kiel,
Germany are undertaking a long-term, extensive
study of the gas hydrates found in the Hydrate
Ridge area off the coast of Oregon and will be
active participants in the NEPTUNE scientificprogram. We are also in the process of defining thelevel of participation of a consortium of Japaneseinstitutions.
IMPLEMENTATION
Phase 2, Development, was formally launchedin September 2000 and is loosely defined as all
activities between completion of the Feasibility
Study and the initiation of activities for Phase 3,
Installation. A major Phase 2 effort is theestablishment of science working groups. Their task

will be to conceptualize the design and develop the
prototypes of the community experiments.
Activities during Phase 3, Installation, areprocurement and deployment of the NEPTUNE
backbone infrastructure with the initial suites of
sensors for community experiments. Phase 4,
Operations, will revolve around four functions:network operations, data management, sensor
network maintenance, and node and cablemaintenance.
COST ESTIMATES
The estimated cost for the NEPTUNE platescale infrastructure is $100M. A rough estimate forthe cost of a suite of community experiments is$100M, of which $15M is for development.
Operating costs are expected to be about$10M/year. (All costs are in year-2000 U.S.
dollars.)
SUMMARY
The history of science shows that newtechnologies such as telescopes and microscopes
commonly result in discoveries that are difficult topredict. By providing continuous access to the time
domain in a well-defined spatial context,
NEPTUNE will enable quantum leaps in our
understanding of processes in the ocean andunderlying lithosphere. These leaps in turn willtranslate into a greatly improved ability to modeland predict the behaviors of these dynamic parts ofour environment and their impact on our social andeconomic well being. For the first time, the supplyof substantial amounts of continuous power andtwo-way communications to a diverse set of sensors
and interactive experiments will allow science at
sea to become as rich and unfettered as science on
land.
NEPTUNE will drive improvements in deepsubmergence technology and could provide
unparalleled test beds for robotic exploration of
extreme habitats, dynamic earth systems, andcomplex oceanographic processes. Internet accessto instrument arrays and robotic systems will allow
novel types of involvement by scientists, learners of
all ages, and the general public.
The level of excitement that NEPTUNE and its
capabilities has engendered among members of thebroad marine science community leaves no doubtthat the time to move ahead is now. NEPTUNE’sseries of cabled seafloor instrument sites will
provide a national and international focus forinnovative earth, ocean, and planetary science
investigations, engaging the imaginations ofresearchers and public alike.

REFERENCES
Chave, A.D., H. Kirkham, A.R. Maffei, G.
Massion, H. Frazier, A.M. Bradley, S.J. Gaudet,
W. Wilcock, D.H. Rodgers, P.M. Beauchamp,
J.C. Madden, and B.M. Howe, 2001: The
NEPTUNE Scientific Submarine Cable System.
Paper prepared for SubOptic 2001, FourthInternational Convention on Undersea
Communications, Kyoto, Japan, 20–24 May 2001.
Davis, E.E., K. Becker, K. Wang and B. Carson,
1995: Long-term observations of pressure andtemperature in Hole 892B, Cascadia Accretionary
Prism. In: Proc. ODP, Sci. Results, 146 (Pt. 1). B.
Carson, G.K. Westbrook, R.J. Musgrave and E.
Suess, eds., Ocean Drilling Program, College
Station, TX, 299–311.
Delaney, J.R., G.R. Heath, B. Howe, A.D. Chave,
H. Kirkham, 2000: NEPTUNE: Real-time oceanand earth sciences at the scale of a tectonic plate.
Oceanography, 13, 71–79.
Delaney, J.R., D.S. Kelley, M.D. Lilley, D.A.
Butterfield, J.A. Baross, W.S.D. Wilcock, R.W.
Embley and M. Summit, 1998: The quantum
event of oceanic crustal accretion: Impacts of
diking at mid-ocean ridges. Science, 281, 222230.
Fluck, P., R.D. Hyndman and K. Wang, 1997:
Three-dimensional dislocation model for greatearthquakes of the Cascadia subduction zone. J.
Geophys. Res., 102, 20,539-20,550.
Glenn, S. M., T.D. Dickey, B. Parker and W.
Boicourt, 2000: Long-term real-time coastal
ocean observation networks. Oceanography, 13,
24-34.
Haidvogel, D.B., J. Blanton, J.C. Kindle and D.R.
Lynch, 2000: Coastal ocean modeling: Processes
and real-time systems. Oceanography, 13, 35-46.

McDonald, M.A. and C.G. Fox, 1999: Passive
acoustic methods applied to fin whale population
density estimation. J. Acoust. Soc. Am., 105,
2643-2651.
National Research Council (NRC) (2000),
Illuminating the Hidden Planet: The Future of
Seafloor Observatory Science, National Academy
Press, Washington D.C.
NEPTUNE Phase 1 Partners (University ofWashington, Woods Hole Oceanographic
Institution, Jet Propulsion Laboratory, Pacific
Marine Environmental Laboratory), 2000: Realtime, Long-term Ocean and Earth Studies at the
Scale of a Tectonic Plate. NEPTUNE Feasibility
Study (prepared for the National Oceanographic
Partnership Program), University of Washington,
SeattleNittrouer, C.A. and L.D. Wright, 1994: Transportof particles across continental shelves. Rev.
Geophys., 32, 85-113.
Smith, K.L., Jr., R.C. Glatts, R.J. Baldwin, S.E.
Beaulieu, A.H. Uhlman, R.C. Horn and C.E.
Reimers, 1997: An autonomous, bottomtransecting vehicle for making long time-series
measurements of sediment community oxygen
consumption to abyssal depths. Limnol.
Oceanogr., 42, 1601-1612.
Suess E., M. Torres, G. Bohrmann, R. Collier, J.
Greinert, P. Linke, G. Rehder, A. Trehu, K.
Wallmann, G.Winckler and E. Zuleger, 1999: Gas
hydrate destabilization: Enhanced dewatering,
benthic material turnover and large methane
plumes at the Cascadia convergent margin. Earth
Plan. Sci. Lett., 170, 1-15.
Wang, K., J. He and E. E. Davis, 1997: Transformpush, oblique subduction resistance, andintraplate stress of the Juan de Fuca plate. J.
Geophys.
R e s. ,102,
661-674