MARGINS News Archive 2004













December 2004

December 21, 2004: EOS article: New Integrated Data Management System for Ridge2000 and MARGINS Research

The EOS article (New Integrated Data Management System for Ridge2000 and MARGINS Research, Carbotte et al., EOS 85 no. 51, 21 December 2004) presents the benefits of the integrated data management system (DMS) for Ridge2000 and MARGINS. It outlines database structure, visualization tools, and future plans for the DMS. [The online article is available only to subscribing individuals or institutions via:].

December 3, 2004: Coupling of slow slip events with deep tremors in SW Japan

Researchers from the National Research Insititute for Earth Science and Disaster Prevention, Tsukaba, Japan have published results suggesting that episodic slow slip events observed as tilt changes in the western Shikoku area of southwest Japan are coincident with major non-volcanic deep subduction zone tremors in the area (Episodic slow slip events accompanied by non-volcanic tremors in southwest Japan subduction zone, Obara et al., Geophysical Research Letters paper 10.1029/2004GL020848).

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November 2004

November 24, 2004: Remotely operated camera to visit bottom of the Mariana Trench

Wired Magazine reports that a team of biologists, oceanographers and two of Jacques Cousteau's grandchildren will join photographer Emory Kristof in dropping a remotely operated camera to the bottom of the Mariana Trench. They hope to obtain "the first photographic core sample" of the ocean from surface to 7 miles down. [Dive! Dive! Dive!, Wired Magazine, December 2004].

November 24, 2004: Senate confirms Arden Bement as director of the NSF

Arden Bement has been acting director of the National Science Foundation (NSF) since Rita Colwell retired early in 2004. Following his nomination by President Bush, the Senate have confirmed his appointment. [Science Now article].

November 23, 2004: Omnibus Budget Bill sees cuts in NSF, EPA and NOAA; USGS about level.

Congress passed the Omnibus Bill - a bundle of science appropriations bills for 2005 funding - on November 20. Several agencies saw cuts, with NASA a notable exception. NSF was cut for the first time in 20 years. More information can be found in the AGU Science Leglislative Alerts 04-15 and 04-16, and Science Now article.

November 18, 2004: Does upper plate structure control subduction zone great earthquake rupture limits?

A paper in the Journal of Geophysical Research (Are rupture zone limits of great subduction earthquakes controlled by upper plate structures? Evidence from multichannel seismic reflection data acquired across the northern Ecuador-southwest Columbia margin, Collot et al., Journal of Geophysical Research paper 10.1029/2004JB003060) asks whether the rupture limits of great earthquakes in a subduction zone are controlled by fault structure of the upper plate. The authors use multichannel seismic data and bathymetry to resolve major transverse crustal faults in the mantle wedge that have apparently terminated coseismic slip along-strike of the northern Ecuador-southwest Columbia margin during past great earthquakes.

November 18, 2004: Modeled evolution of U-Th-Pb and Sm-Nd in plate tectonics

A numerical model has been used to investigate the development of U-Th-Pb and Sm-Nd systems in a convecting mantle (Evolution of U-Pb and Sm-Nd systems in numerical models of mantle convection and plate tectonics, Xie and Tackley, Journal of Geophysical Research paper 10.1029/2004JB003176). The model includes melting-induced differentiation (via secular cooling, radiogenic heat production and mineral phase transitions) and tracking of elements through the system, in a simplified plate tectonic system. The models consistently develop certain characteristic signatures consistent with observations in some fundamental ways, but with notable discrepancies. The authors discuss both the successes and the limitations of the model.

November 11, 2004: Evidence for forearc mantle wedge serpentinization in the MARGINS Central America focus site

Inversion of seismic arrival times recorded as part of the Costa Rica Seismogenic Zone Experiment has been used to generate 1D and 3D velocity models of the subduction zone along the Nicoya Peninsula (Evidence for serpentinization of the forearc mantle wedge along the Nicoya Peninsula, Costa Rica, DeShon and Schwartz, Geophysical Resarch Letters paper 10.1029/2004GL021179). Because the results are consistent with 15-25% serpentinization of the forearc mantle wedge, there are important implications for frictional stability at the downdip edge of subduction megathrusts in the region.

November 9, 2004: Segmentation of slip in the seismogenic zone of plate subduction in Central America

A paper published in the Journal of Geophysical Research (Geodetic and seismic constraints on some seismogenic zone processes in Costa Rica, Norabuena et al., Journal of Geophysical Research paper 10.1029/2003JB0002931) reports insights into Costa Rica seismogenic zone segmentation observed using new seismic (onshore/offshore) and geodetic data. The data suggest locked patches centered at two depths (14+/-2 km and 39+/-6km) between the subducting and overriding plates in the vicinity of the Nicoya Peninsula (northern Costa Rica), with microseismic activity representing ongoing slip between the two. By contrast, the Cocos plate-Panama block boundary (southern Costa Rica) appears to be completely locked. The authors discuss the structural differences between these two regions of subduction, and consider the implications for potential rupture limits in future large earthquake events.

November 5, 2004: Experimental work suggests that frictional melting can terminate seismic slips

An experimental method applied by scientists at the universities of Tohoku and Niigata, Japan, has allowed them to detect the exact timing of frictional melting in laboratory simulated stick-slip events (Frictional melting can terminate seismic slips: Experimental results of stick-slips, Koizumi et al., Geophysical Research Letters paper 10.1029/2004JB003176). Their results show initial friction reduction during slip, terminated by an abrupt strengthening coincident with the onset of melting on the slip surfaces.

November 3, 2004: Canterbury Basin, New Zealand, marine sequence boundaries apparently controlled by global sea-level variations and local ocean currents

Researchers from the University of Texas, Austin, Texas, have used multichannel seismic reflection profiles tied to boreholes to identify nineteen unconformably stacked sedimentary units in the offshore Canterbury Basin, eastern South Island, New Zealand (Controls on sequence stratigraphy of a middle Miocene-Holocene, current-swept passive margin: Offshore Canterbury Basin, New Zealand, Lu and Fulthorpe, GSA Bulletin 116, #11, pp. 1345-1366). Global climate change and sequence geometry suggest that global sea-level cycles from the middle Miocene onwards have controlled unconformity formation, but that sequence geometries have been locally controlled by ocean currents.

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October 2004

October 28, 2004: NSF funds creation of first international registry of solid earth samples

The Earth Institute at Columbia University has announced that Kristen Lehnert is leading a project at Lamont Doherty Earth Observatory to develop a "Solid Earth Sample Registry" (SESAR), probably by the end of 2004. The NSF-supported project will develop a digital registry to provide globally unique identifying serial numbers to all registered samples. These "International Geo Sample Numbers" (IGSNs) will be digitally stored along with primary information about the sample and its origin, collector/owner, location, etc. Once implemented, this system will overcome historical problems with relocated samples losing their "identity" and with inconsistent naming of samples across institutions and nations. The result will facilitate sharing of data, linking of databases, and international collaboration. [Press release]

October 21, 2004: Imaging deep Earth motion

A wide-angle marine seismic experiment recorded by 100 ocean-bottom seismometers along the Nankai trench, Japan, has been used to obtain exceptionally high resolution images of the Nankai subduction system (Multiscale seismic imaging of the eastern Nankai trough by full waveform inversion, Dessa et al., Geophysical Research Letters paper 10.1029/2003JB002689). The new analysis technique - involving crustal-scale 2D full waveform inversion - resolves velocity variations that likely indicate fluids and weakened material that may influence seismic slip at depth.

October 7, 2004: InterMARGINS "Extensional Deformation of the Lithosphere" Workshop posters and presentations available online

As a resource for the participants, scientists, and the public, digital presentations and posters from July's InterMARGINS "Extensional Deformation of the Lithosphere" Workshop (IMEDL), Pontresina, Switzerland, have been made available online through the Workshop website: Content ranges from observational talks relating to key features of extensional zones globally, to numerical modeling of extensional systems. In many cases, authors have added footnotes to their presentations to help the casual reader.

October 5, 2004: A major addition to the InterMARGINS web site

A major new section, titled "Global Information", on the InterMARGINS web site ( has been announced. The new section provides a valuable resource that brings together numerous charts and other information about the Earth on a global scale. The original purpose was to provide cruise planners with information that might be helpful for planning a proposal or cruise to an unfamilar location. But this objective has been exceeded and a great deal of the information will be of use, for example, in teaching.

October 2, 2004: Evidence for a subduction zone locked fault zone extending into the mantle

In contrast to a current view, new research (The Sumatra subduction zone: A case for a locked fault zone extending into the mantle , Simoes et al., Journal of Geophysical Research paper 10.1029/2003JB002958) appears to demonstrate a locked fault zone extending to depths of 35km to 57km (260 +/- 100degreesC) in the Sumatra subduction zone. The authors suggest that aseismic slip at greater depths is probably by steady state brittle sliding rather than ductile flow.

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September 2004

September 30, 2004: Prototype infrastructure to provide research and educational access to remote undersea sensor networks

The National Science Foundation is funding prototype systems for onland control of undersea sensor networks and remote data provision via cyberinfrastructure (e.g., web services and protocols using wireless and optical networks). The multi-institution LOOKING (Laboratory for the Ocean Observatory Knowledge Integration Grid) group - funded to the tune of $3.9 million over four years - will collaborate on the technology needed to provide high-speed links from ocean observatories around the US, Canada and Mexico to oceanographic communities. As well as facilitating control of equipment in remote and hostile environments, tools will be developed to maximise research and education applications. [UCSD Press Release on Eureka Alert].

September 25, 2004: Seismogenic energy release at subduction zones

Investigation of earthquake source time functions has been used to allow systematic comparison of energy release - and hence rupture process - by depth within and between subduction zones (Radiated seismic energy and earthquake source duration variations from teleseismic source time functions for shallow subduction zone thrust earthquakes, Bilek et al., Journal of Geophysical Research paper 10.1029/2004JB003112).

September 23, 2004: Seismic imaging of the eastern Nankai trough

A paper in Geophysical Research Letters (Multiscale seismic imaging of the eastern Nankai trough by full waveform inversion, Dessa et al., Geophysical Research Letters paper 10.1029/2004GL020453) investigates the eastern Nankai subduction system using 2-D crustal-scale full waveform inversion for the first time. The resulting high resolution velocity models reveal possible coseismic slip partitioning structure, along with major faults, structural discontinuities and compressive tectonic features.

September 21, 2004: MARGINS Posts NSF Review Materials

The U.S. MARGINS program recently underwent a five-year review at NSF, in which the program was evaluated by a committee of scientists not currently involved with the MARGINS Program, or receiving MARGINS funding. This review - which is fairly standard for long-running programs - was a valuable opportunity for the MARGINS Steering Committee (MSC) and Office to carry out a self-review. Having now received from NSF a public summary of the MARGINS Review Committee (MRC) report, the MARGINS Office are pleased to publish the review documents through a dedicated section of the MARGINS website

September 20, 2004: "An Ocean Blueprint for the 21st Century" - The U.S. Commission on Ocean Policy delivers its Final Report to Congress

The U.S. Commission on Ocean Policy's Final Report gives recommendations for a comprehensive national ocean policy for the 21st Century. As such, it is a key document for all those interested in potential directions for future U.S. ocean research. Under the terms of the Oceans Act of 2000, within 90 days President George W. Bush must submit a statement to Congress in response to the report. The U.S. Commision on Ocean Policy website ( details the history and role of the Commission, provides background documents, and offers the Final Report and a summary of its 212 recommendations in full, or in segments.

September 16, 2004: MARGINS research cruise data show 8-10 million year old major tectonic event off Costa Rica

Reflection seismic data collected during two research cruises have been correlated with Ocean Drilling Project core data to reveal a major tectonic event off Costa Rica, 8-10 million years ago (An 8?10 Ma tectonic event on the Cocos Plate offshore Costa Rica: Result of Cocos Ridge collision? , Silver et al., Geophysical Research Letters paper 10.1029/2004GL020272). Features of this event included magma intrusion from the Galapagos hotspot, local faulting, and tilting of ridges across a wide area; perhaps due to to collision of the Cocos Ridge with Costa Rica at around that time.

September 16, 2004: Arden Bement, National Science Foundation Acting Director, nominated as new Director of the Foundation

President Bush has nominated Arden Bement as the new Director of the National Science Foundation. [AGU Science Legislative Alert | White House press release]

September 16, 2004: Smithsonian ocean science program announced

The Smithsonian Institution National Museum of Natural History and NOAA are jointly launching a new ocean science program. The program will establish the Ocean Science Initiative to bring ocean science to the public, and will see a new Ocean Hall open in the museum in 2008. [Associated Press report, through Yahoo! News]

September 14, 2004: From sniffing out subs to ocean exploration: U.S. Navy ship going to NOAA

The USNS Capable - a quiet-running Navy vessel designed for surveillance and drug interdictions - will be handed over to NOAA after an $18 million conversion. It will be the first vessel under sole control of NOAA's Office of Ocean Exploration. The low noise and maneuverability demanded by Navy roles such as tracking submarines make the vessel ideal for its new purpose. The refit will see the addition of new facilities including sensors for seafloor imaging and equipment for deploying unmanned submarines. Following a growing trend in public outreach, onboard conferencing will allow live audio-visual broadcasts from the ship to classrooms and other facilities. [Associated Press report, through Yahoo! News]

September 3, 2004: Highest honor awarded by NSF is accepting applications

The 2005 Alan T. Waterman Award recognizes outstanding young researchers supported by the National Science Foundation. The awardee receuves a $500,000 nonrestrictive continuing research grant over a 3 year period. Eligibility is restricted to those 35 years old or younger, or not more than seven years beyond receipt of their Ph.D. by December 31, 2004. Nomination deadline is November 30, 2004. Other restrictions apply. [NSF Announcement | NSF Honorary Awards]

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August 2004

August 19, 2004: The MARGINS News page has changed

If you are familiar with the MARGINS News page then you will see that all is not as it was. As part of our efforts to engage and inform the community, the MARGINS Office has broadened the range of news that it monitors for issues of relevance to MARGINS science and scientists. The result will be more information appearing more frequently, with sources including: the mainstream media, such as Reuters: Science, BBC News - Science, and Yahoo! News - Science; popular science journals, such as New Scientist and Nature; academic journals; environmental groups; and policy makers and informers, such as NSF, NOAA, the U.S. House Committee on Science, and the Commission on Ocean Policy. We hope that you will find this a valuable resource and welcome your comments:

August 10, 2004: Seismic tomography evidence for subduction along the full length of the New Guinea Trench

Seismic tomography imaging of the downgoing slab (Evidence for active subduction at the New Guinea Trench, Tregoning and Gorbatov, Geophysical Research Letters (GL) paper 10.1029/2004GL020190, 2004) confirms evidence from earlier studies that the New Guinea Trench is an active subduction zone.

August 10, 2004: Seismic velocity model shows origins of magma supplying the Taupo Volcanic Zone, New Zealand

Analysis of seismic velocity data from below the Taupo Volcanic Zone, New Zealand (Crustal structure of the Taupo Volcanic Zone, New Zealand: Stretching and igneous intrusion, Harrison and White, Geophysical Research Letters (GL) paper 10.1029/2004GL019885, 2004), suggests that magma rises to a depth of 15-30km in the crust, where interaction with the lower crust alters the melt before it rises into the volcanic zone. For the magma source, the authors propose that mantle melting above the subducting Pacific Plate is induced by release of water from material carried down with it.

August 4, 2004: Alvin replacement will dive deeper

The research submarine Alvin will be replaced with a deeper diving human-operated vehicle (HOV) in 2008. The replacement will be funded by the NSF through a cooperative agreement with the Woods Hole Oceanographic Institute (WHOI). The new HOV will have a depth limit of 6,500m (21,320 feet). That's 2000m deeper than Alvin - which began operation in 1964. [NSF press release].

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July 2004

July 28, 2004: Marine Mammal update

July 28th: Ocean Scientists Assess Impact of Seismic Pulses in Effort to Protect Whales - Researchers investigating the possible effect of underwater seismic pulses on marine mammals have conducted a series of tests, designed to better understand how far and how strongly sound waves produced by marine acoustic sources travel in both deep and shallow water. Their study is detailed in Geophysical Research Letters (Broadband calibration of R/V Ewing/seismic sources, Tolstoy et al., Geophys. Res. Lett., 31, L14310, doi:10.1029/2004GL020234).

July 22nd: A BBC News Online article ( reports an International Whaling Commission (IWC) scientific committee report assessing potential effects of intense man-made underwater noise on marine mammals. A link to the IWC report will be added here once available.

June 25th: Reuters report a U. S. Office of Naval Research funded study to investigate how whales perceive and use sound. Full article (through ABC News)

June 16th: An article in New Scientist (Cold waters leave whales washed up, Emma Young, New Scientist 183, issue 2456, p12) reports research by Mark Hindell's team at the Antarctic Wildlife Research Unit, University of Tasmania, Hobart, finding that anomalous peaks in annual south-east Australia whale strandings oiver the last 80 years correlate with cold water episodes on a 10-12 year cycle. Full article.

An archive of Marine Mammal updates, together with other relevant information is available on the MARGINS Ocean Noise and Marine Mammals page.

July 21, 2004: 2005 budget delays could impact new projects funded through US science agencies

An article in Nature (Budget delays threaten to leave US science in limbo, Geoff Brumfiel, Nature doi:10.1038/430388b), suggests that likely delays to the fiscal year 2005 budget could leave agencies at 2004 levels into early 2005. As of 21 July, with none of the 13 spending bills for government funding complete, Congress summer recess starting on 23 July, and the presidential election in November; the budgets may not be resolved until as late as February or March 2005. Such a delay could stimmy new project funding, even though large increases are not expected for most agencies.

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July 16, 2004: Restructuring of NSF Division of Earth Sciences

With an effective date of 1 Augu, 2004, the NSF Division of Earth Sciences is to be realigned in two new Sections: Surface Earth Processes (SEP) and Deep Earth Processes (DEP). As stated in a "Dear Colleague" letter dated 16 July 2004, the Division is realigning from their long established, but now outmoded, Research Grant Section and Special Project Section format.

A second "Dear Colleague" letter, also dated 16 July 2004, invites applications to fill the position of Head of the new EAR Surface Earth Processes Section. This position was previously advertised as Head, Research Grants Section.

July 15, 2004: Dr. Rita Calwell, former head of the NSF, to be inducted into the National Women's Hall of Fame [House Committee on Science press release]

July 14, 2004: NSF has released its updated grant proposal guide, active September 1, 2004. [HTML, PDF]

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June 2004

June 25, 2004: Inaugural voyage of the Integrated Ocean Drilling Program (IODP) underway

The inaugural voyage of the Integrated Ocean Drilling Program (IODP) is being touted as the "largest research expedition of its kind" in a Joint Oceanographic Institutions press release . The expedition will study fluid flow within the upper oceanic crust at the Juan de Fuca Ridge, using hydrologic, microbiological, seismic, and tracer studies.

June 18, 2004: Second draft bill for a NOAA Organic Act

The Bush Administration's proposed National Oceanic and Atmospheric Administration Organic Act (H.R. 4607) was introduced to the House Committee on Science today. The act was drafted in response to findings of the U.S. Commission on Ocean Policy and is more general than H.R. 4546 (see June 14th release, below). The act would tie together NOAA agency funding into a single annual budget, avoiding the complex combination of funding, and differing public laws and committees of jurisdiction, under which NOAA currently operates, and formalizing NOAA's role. [House Committee on Science press release ]

June 15, 2004: Permitting requirements affect proposals for NSF-funded seismic survey cruises

A memorandum by Michael R. Reeve, Head, Integrated Programs Section (Acquisitions and Operations), Division of Ocean Sciences, National Science Foundation, details issues affecting "New Proposals for Projects Involving Seismic Survey Cruises Beyond 2005." [ Memorandum |Announcements ]

June 14, 2004: First draft bill for a NOAA Organic Act

Environment, Technology, and Standards Subcommittee Chairman Vernon Ehlers' (R-MI) proposed National Oceanic and Atmospheric Administration Act (H.R. 4546) was introduced to the House Committee on Science today. The act aims to more clearly define NOAA's Responsibilities and authority, with specific reference to many of the findings of the U.S. Commission on Ocean Policy (see April 20th release, below). [House Committee on Science press release ]

June 8, 2004: Norwegian research ship fired upon by Equatorial Guinea Coastguard, captain detained overnight

BBC News online reports an incident in which the Norwegian research ship Fridtjof Nansen was hit by several bullets, and the captain and chief engineer were held overnight by the Equatorial Guinea Coastguard. The ship was surveying fish stocks for the United Nations World Food Program. [ Full article ]

June 7, 2004: Adriatic likely seismically independent fault system

A series of simple models shows that the Adriatic plate is likely not connected to the Eurasian or Nubian (African) tectonic plates as has been previously thought. Battaglia et al. used geodetic data to constrain the boundaries and seismic potential of the Adriatic fault system in the Mediterranean basin. Their evidence depicts the Adriatic as moving in sharp contrast to the direction of the two larger plates, suggesting that the Adriatic is an independent microplate within the collision zone. The authors used Global Positioning System measurements and modeling techniques to analyze the surface movements within the region, whose tectonics are not well known, and explain deformation previously observed near the Mediterranean Sea. The researchers propose that the Adriatic microplate is blocked within several faults and, although they cannot predict the specific number or location of the faults, find that their estimates agree with previous studies and actual events.

Title: The Adriatic region: An independent microplate within the Africa-Eurasisa collision zone

Authors: Maurizio Battaglia, University of California, Berkeley, California, and National Institute for Oceanography and Geophysical Studies, Seismological Research Center, Udine, Italy; Mark H. Murray, Roland Burgmann, University of California, Berkeley, California; Enrico Serpelloni, National Institute for Geophysical and Volcanological Study, Bologna, Italy.

Source: Geophysical Research Letters (GL) paper 10.1029/2004GL019723 , 2004.

June 7, 2004: First turbidity measurements from inside strong California current

The first measurements of turbidity currents from inside the deep Monterey Submarine Canyon off the California coast provides details of the currents that drive sediments into the open ocean. Xu et al. present preliminary data from their experiment that placed three Doppler current profile instruments at depths between approximately 800-1500 meters [3,000-5,000 feet]. The authors observed maximum velocities of more than 190 centimeters [6.2 feet]per second, or slightly over six kilometers [4 miles] per hour, during four turbidity currents, including two that coincided with surface storms between 2002 and 2003. The fast-moving, destructive currents had hampered previous attempts to monitor the canyon currents by damaging or burying the sensors designed to measure water velocity and dynamics generated by the sediment-laden water. Their findings show that although the current turbidity was confined to within 50 meters [200 feet] of the canyon floor, the sediment plumes from the underwater currents reached more than 170 meters [560 feet] above the floor.

Title: In-situ measurements of velocity structure within turbidity currents

Authors: Jingping Xu, M. A. Noble, U.S. Geological Survey, Menlo Park, California; L. K. Rosenfeld, Naval Postgraduate School, Monterey, California.

Source: Geophysical Research Letters (GL) paper 10.1029/2004GL019718 , 2004.

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May 2004

May 29, 2004: Can a dinosaur skull change estimates of how recently Africa separated from Gondwanaland?

The first discovery of an abelisaurid skull in Africa provides evidence that Africa was still connected to Gondwanaland more recently than current estimates of around 120 million years ago ( New dinosaurs link southern landmasses in the Mid-Cretaceous , Paul C. Sereno, Jeffrey A. Wilson, & Jack L. Conrad, Proceedings: Biological Sciences 271, number 1546, p1325-1330). Rugops primus - as the 95 million year old dinosaur has been named by the group that discovered it - is closely related to other abelisaurids in South America, Madagascar and India: suggesting that Africa was still connected to Gondwanaland around 100 million years ago. [ Associated Press report , through ABC News]

May 26, 2004: Using background noise to improve seismic models

Researchers have devised a new way to interpret natural seismic noise recorded by existing receivers that may improve the accuracy of efforts to map the Earth's interior. Shapiro and Campillo show a technique to extract Rayleigh waves, a type of surface wave with known characteristics, from observations of ambient seismic noise caused by oceanic and atmospheric sources. Surface waves produced during earthquakes are commonly used to generate seismic tomographic maps, but such events cannot provide reliable models, because of their wide distribution over the Earth's surface and the difficulty of determining the source of the seismic waves. The authors suggest that a new method can be created to use the surface-wave dispersion characteristics measured from the background seismic noise that will be able to improve the resolution of seismic tomographic models.

Title: Emergence of broadband Rayleigh waves from correlations of the ambient seismic noise
Authors: Nikolai M. Shapiro, University of Colorado, Boulder, Colorado; M. Campillo, Joseph Fourier University and French National Research Center, Grenoble, France.
Source: Geophysical Research Letters (GL) paper 10.1029/2004GL019491 , 2004

May 17, 2004: NASA and USGS Magnetic Database to provide insights into Earth's geology and magnetism

A new database being compiled by NASA and the USGS will combine magnetic data from over 36,000 rock samples with satellite magnetic field data in a single resource. [ NASA Web Feature ]

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April 2004

April 30, 2004: Examining post-seismic slip after Japanese earthquake

Data from Global Positioning System (GPS) satellites indicate that post-seismic slip following the powerful 2003 Tokachi-oki earthquake in Japan was concentrated adjacent to, rather than within, the earthquake rupture zone. Miyazaki et al. examined the displacement at GPS sites on the island of Hokkaido in the month following the 8.0-magnitude earthquake and found a shift of approximately two centimeters [0.8 inches] immediately after the event, which rapidly slowed to nearly one centimeter [0.4 inches] per day for the following two weeks. The authors note that the earthquake occurred in nearly the same area as a strong temblor in 1952, although it is unclear whether past earthquakes have ruptured the post-seismic areas. The researchers suggest that the character of the afterslip movement may reflect variability in a fault zone's frictional properties, noting how such movement increased the stress at the hypocenter of two other Japanese earthquakes in 1968 and 1973.

Title: Space time distribution of afterslip following the 2003 Tokachi-oki earthquake: Implications for variations in fault zone frictional properties

Authors: Shinichi Miyazaki, Stanford University, Stanford, California, and Earthquake Research Institute, University of Tokyo, Tokyo, Japan; P. Segall, Stanford University, Stanford, California; J. Fukuda, T. Kato, Earthquake Research Institute, University of Tokyo, Tokyo, Japan.

Source: Geophysical Research Letters (GL) paper 10.1029/2003GL019410 , 2004

April 26, 2004: The MARGINS and National Marine Sciences Seismic Reflection Databases are online and accepting submissions. See the Announcements page for more details.

April 26, 2004: Following the MARGINS Steering Committee (MSC) meeting of April 1-2, 2004, the MSC said a grateful and regretful farewell to Tom Shipley (University of Texas Institute for Geophysics) and Greg Hirth (Wood's Hole Oceanographic Institution), as they rotated off the MSC. We greatly appreciate Tom's many years of contributions to the development of the SEIZE initiative, the MARGINS data policy and database development and the shaping of MARGINS activities overall. Greg's unique ability to integrate laboratory and theoretical work to constrain the rheological and physical properties of the Earth and their geodynamic implications exemplifies the MARGINS philosophy of interdisciplinary study of fundamental processes, and his excellent integrative advice will be greatly missed. Our thanks to you both, and best wishes.

April 20, 2004: U.S. Commission on Ocean Policy Preliminary Report makes recommendations for "Organic Act" to strengthen NOAA's future.

The U.S. Commission on Ocean Policy today released its Preliminary Report . Among its recommendations is that, "the National Oceanic and Atmospheric Administration (NOAA) should be reconfigured and strengthened to better enable it to execute its many ocean- and coastal-related responsibilities." "Immediate Action: Solidify NOAA's role as the nation's lead civilian ocean agency through the enactment of a NOAA organic act that codifies the agency's establishment within the Department of Commerce, clarifies its mission, and strengthens execution of its functions."

April 2, 2004: Last year the NOAA Ocean Exploration Program funded a survey of the Mariana Arc. During that survey a number of hydrothermal systems on the arc volcanos were identified.  The February 2003 CTD tow over NW Rota 1 (14 deg. 36.1'N; 144 deg. 46.5'E) was of particular interest because its chemical character implied recent magmatic activity.  During the last few days, dives with the remotely operated vehicle ROPOS have documented phenomena that indicate NW Rota 1 is in a magmatic phase of activity. Direct evidence for this includes: (1) an active volcanic vent showing time-varying activity, including precipitation of sulfur in the volcanic vent (with partly molten sulfur balls ejected in large quantity), pulses of volcanic ejecta coming from same, and (2) large amounts of fresh, glassy volcanic ejecta surrounding the volcanic crater at the summit (555 m depth).  In addition, a very interesting turbid plume around the flank of the volcano extending from about 700 m to at least 2000 meters has beenfound . This is a totally unique feature in our experience (It was NOT present in 2003) and is very likely related in some way to the summit activity (very possibly volcanic seismicity).

The large amount of sulfur is believed to be forming by interaction of magmatic SO2 with water to form elemental sulfur and sulfuric acid. The magmatic character of this activity is a real opportunity to realize science objectives of the Subduction Factory Experiment, especially in the realm of volatile budgets (S, CO2, He). We also think that this magmatic event is in its early stages, as evidenced by negligible alteration of glassy lavas in spite of incredibly corrosive hot fluids and by a biota that team biologists tell us is only beginning to colonize the area. We are now moving north to look at other targets along the arc after 4.5 days at the site. There is an active website for the cruise that has more information, including seafloor images of the phenomena observed at NW Rota I.

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March 2004

• March 30, 2004: Visit a new website created by MARGINS scientists on expedition to the Marianas:

The expedition starts 11 April with a fly-over of the islands followed by departure of the ship on the 14th. Reseachers will be updating the website with daily reports (movies, text and pictures) from that time onward.

• March 26, 2004: GPS method to track ground movement after earthquakes

A rapid processing technique using Global Positioning System data to measure the land movement following an 8.0-magnitude earthquake in Japan may provide a simpler method to improve researchers' knowledge of the seismic cycle after such massive tremblors. Miura et al. used GPS coordinates before and after the 2004 Tokachi-Oki earthquake to estimate the slip distribution on the plate boundary. The subducting tectonic plates near that portion of northern Japan move approximately 80 millimeters [three inches] per year, making them two of the most seismically active areas in the world. The GPS data were attributed to a maximum co-seismic slip of approximately five meters [20 feet] near the quake's offshore epicenter, which agree with other displacement estimates. The authors note that the existing GPS network in Japan can continue to measure the co- and post-seismic slip distribution around the plate boundaries.

Title: The 2004 M8.0 Tokachi-Oki earthquake: How much has the great event paid back slip debts?

Satoshi Miura, Yoko Suwa, Akira Hasegawa, Research Center for Prediction of Earthquakes and Volcanic Eruptions, Tohoku
University, Sendai, Japan; Takuya Nishimura, Geography and Crustal Dynamics Research Center, Geographical Survey Institute, Tsukuba, Ibaraki, Japan.

Source: Geophysical Research Letters (GL) paper: 10.1029/2004GL019021, 2004

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February 2004

• February 27th, 2004: Congratulations to all those that entered our first annual student competition, which took place at the AGU 2004 Fall Conference. All 31 applicants have ably expressed a desire and the capability to expand the boundaries of their science. All applicants to the competition were winners, and we recognize several that have demonstrated great promise for the years to come. [MORE]

• February 3, 2004: New MARGINS Website
The MARGINS website has undergone a chance in appearance.

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January 2004

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MARGINS News Archive 2004

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Last updated Friday, January 19, 2007