IN51B-0400
Sea Level Station Metadata for Tsunami Detection, Warning and Research
The devastating earthquake and tsunami of December 26, 2004 has greatly increased recognition of the need for water level data both from the coasts and the deep-ocean. In 2006, the National Oceanic and Atmospheric Administration (NOAA) completed a Tsunami Data Management Report describing the management of data required to minimize the impact of tsunamis in the United States. One of the major gaps defined in this report is the access to global coastal water level data. NOAA's National Geophysical Data Center (NGDC) and National Climatic Data Center (NCDC) are working cooperatively to bridge this gap. NOAA relies on a network of global data, acquired and processed in real-time to support tsunami detection and warning, as well as high-quality global databases of archived data to support research and advanced scientific modeling. In 2005, parties interested in enhancing the access and use of sea level station data united under the NOAA NCDC's Integrated Data and Environmental Applications (IDEA) Center's Pacific Region Integrated Data Enterprise (PRIDE) program to develop a distributed metadata system describing sea level stations (Kari et. al., 2006; Marra et.al., in press). This effort started with pilot activities in a regional framework and is targeted at tsunami detection and warning systems being developed by various agencies. It includes development of the components of a prototype sea level station metadata web service and accompanying Google Earth-based client application, which use an XML-based schema to expose, at a minimum, information in the NOAA National Weather Service (NWS) Pacific Tsunami Warning Center (PTWC) station database needed to use the PTWC's Tide Tool application. As identified in the Tsunami Data Management Report, the need also exists for long-term retention of the sea level station data. NOAA envisions that the retrospective water level data and metadata will also be available through web services, using an XML-based schema. Five high-priority metadata requirements identified at a water level workshop held at the XXIV IUGG Meeting in Perugia will be addressed: consistent, validated, and well defined numbers (e.g. amplitude); exact location of sea level stations; a complete record of sea level data stored in the archive; identifying high-priority sea level stations; and consistent definitions. NOAA's National Geophysical Data Center (NGDC) and co-located World Data Center for Solid Earth Geophysics (including tsunamis) would hold the archive of the sea level station data and distribute the standard metadata. Currently, NGDC is also archiving and distributing the DART buoy deep-ocean water level data and metadata in standards based formats. Kari, Uday S., John J. Marra, Stuart A. Weinstein, 2006 A Tsunami Focused Data Sharing Framework For Integration of Databases that Describe Water Level Station Specifications. AGU Fall Meeting, 2006. San Francisco, California. Marra, John, J., Uday S. Kari, and Stuart A. Weinstein (in press). A Tsunami Detection and Warning-focused Sea Level Station Metadata Web Service. IUGG XXIV, July 2-13, 2007. Perugia, Italy.
IN51B-0401
World Wide Web Access to Fluid Inclusion Data for Computational Modelling and Simulation
Accurate constraints on the chemistry of hydrothermal fluids are critical in our capacity to computationally model and simulate how ore deposits form. To maximize results and subsequent interpretation the fluid inclusion populations should be fully characterized using standardised observational and processing techniques. A Virtual Centre for Geofluids and Thermodynamic Data, which includes the fluid inclusion (FIncs) system, has been established to achieve this. The FIncs system is designed to pull together fluid inclusion data from many individual, often disparate studies. The FIncs database and web applications allow researchers to search and retrieve fluid inclusion data and images via a web browser interface. The database will help standardise the way fluid inclusion data and associated metadata are stored. Furthermore, it follows the principles outlined by the Open Geospatial Consortium (OGC) for the Observation and Measurement application schema. It is tightly coupled to enable formalisation of the observations and measurements made on fluid inclusions, and to standardise how these measurements are processed to achieve consistent constraints for geochemical models. FIncs uses both domain factual knowledge and problem-solving knowledge by providing a choice of models (equations of state) for obtaining additional fluid properties via a web-based calculator, which allows researchers to calculate isochoric T&P values and other chemical and physical properties (e.g. salinity, density, etc.). This method has the benefit of ensuring that all derived data are produced and standardised by a selected set of routines. It also enables data from multiple sources to be quickly reprocessed by new routines as they become available and are added to the database toolkit. The database is being developed as an "open" project, which intends to bring together researchers interested in the properties of geological fluids or fluid inclusions. The ultimate goal of the Virtual Centre for Geofluids information system is to provide machine-to-machine (software-to-software) data readability, enabling more or less seamless integration of different datasets and computer codes. In future, users' applications will be able to access the system as web-services using XML. http://www.ga.gov.au/minerals/research/methodology/geofluids/index.jsp
IN51B-0402
Storage and Dissemination of SEGY Data in JPEG2000 Format
The Geological Survey of Canada (GSC) collects over 1 TByte of SEGY (Society of Exploration Geophysicists)- formatted high-resolution seismic and sidescan data each year, and wishes to implement an efficient mechanism for storing, discovering and accessing these data holdings. Currently, scientists often use field- generated paper records in preference to digital data, as accessing and processing existing digital holdings involves excessive effort. Much of our digital holdings have never been examined and their content has not been verified. The GSC is exploring JPEG2000 technology to address these challenges. The JPEG2000 framework, although commonly associated with images, is a wavelet-based compression standard that can accommodate multiplane, signed data arrays with up to 38 bits of resolution. It can generate a multiresolution representation with quality layers and random file access, allowing a quick and quality- progressive peek into file contents. It provides both reversible and lossy compression options. JPEG200 is a flexible file format optimized for transfer over low-bandwidth internet connections and allows the inclusion of user- designed content and more standardized XML boxes for metadata. A Windows-based application was developed to transform single channel SEGY data into JPEG2000 format. An XML schema (XSD) was developed to encode SEGY tape and trace header data into JPEG2000 xml boxes. These XML data will also be used as discovery metadata in GSC's relational databases to describe seismic data holdings. Trace data was encoded in a data array at a bit resolution sufficient to preserve data fidelity since JPEG2000 can encode data at fractional word lengths. A series of trials on existing seismic data sets show that a loss-free conversion of SEGY to JPEG2000 will reduce file size by a factor more than 2:1 but that partial, lossy versions of the same data show no visible artifacts for compression ratios in excess of 20:1. In addition, very large files can be easily and quickly scanned over local networks and the internet using standard JPEG2000 viewers without decoding the entire data stream. Software to convert SEGY to and from JPEG2000 is freely available from the author.
IN51B-0403
Global Navigation Satellite Systems Data Handling, Archiving, Preservation, and Distribution Through the UNAVCO Data Center
The UNAVCO Data Center in Boulder, Colorado, archives for preservation and distributes freely accessible high- precision Global Navigation Satellite System (GNSS) data and products to the scientific and education community. The data, which are useful for geodesy, tectonic, volcanological, ice mass, glacial isostatic adjustment, meteorological and other studies, come from 1500 continuously operating stations and 8000 survey- mode observation points around the globe that are operated by over 100 U.S. and international members of the UNAVCO Consortium. These data represent the efforts of individual investigator research projects, large networks such as the NASA Global GNSS Network, the U.S. Geological Survey southern California network, and the very large EarthScope Plate Boundary Observatory that is funded by the U.S. National Science Foundation. By policy, all permanent GNSS station data from UNAVCO are freely available. The Data Center archives, catalogs, and delivers millions of GNSS data products annually. The Data Center also archives for preservation and distributes spaceborne SAR data that are in many ways complementary to the GNSS data collection. SAR data holdings are being acquired in concert with the WInSAR Consortium activities and the GeoEarthScope project and are subject to data distribution restrictions. The metadata for UNAVCO's GNSS data holdings are stored in an Oracle database that supports a rich set of web-based interactions to allow data search, access, and delivery. A metadata exchange with other GNSS data archives has been in place for nearly ten years allowing participants to show each other's holdings as a seamless archive. Efforts are underway to expand and modernize this type of data and metadata exchange through webservices, Open Geospatial Consortium WFS/WMS services, and to maximize the utilization of freely available spatial display technologies such as GoogleEarth. Many users access the UNAVCO GNSS data archives through automated mechanisms that canvas the ftp area for data that are of recurring interest. Station and data discovery mechanisms are available that allow these users to interact with the UNAVCO metadata through an application programming interface (API) with URI requests and XML responses that enhance the user's ability to find and directly download relevant data and metadata in an automated fashion. http://facility.unavco.org/data/data.html
IN51B-0404
ES3: Automatic capture and reconstruction of science product lineage and metadata
The MODSCAG algorithm derives per-pixel fractional snow-covered area and snow grain size from MODIS imagery. The current implementation of MODSCAG is a combination of UNIX shell scripts, compiled C programs, and interpreted IDL programs. MODSCAG is under active development, and tracing its output products back to specific parameter settings or software versions is crucial for debugging and quality control. To this end, we are running MODSCAG on the Earth System Science Server (ES3), a suite of software that automatically captures run- time information about user processes and stores this information in an XML database, which can be queried to retrieve a specific MODSCAG output's complete lineage graph and any associated metadata. This poster/presentation will illustrate how this lineage/metadata capture operates without any modifications to either the host operating system or the science application code. http://eil.bren.ucsb.edu/agu2007
IN51B-0405
The Global Multi-Resolution Topography (GMRT) Synthesis
Topographic maps provide a backdrop for research in nearly every earth science discipline. There is particular demand for bathymetry data in the ocean basins, where existing coverage is sparse. Ships and submersibles worldwide are rapidly acquiring large volumes of new data with modern swath mapping systems. The science community is best served by a global topography compilation that is easily accessible, up-to-date, and delivers data in the highest possible (i.e. native) resolution. To meet this need, the NSF-supported Marine Geoscience Data System (MGDS; www.marine-geo.org) has partnered with the National Geophysical Data Center (NGDC; www.ngdc.noaa.gov) to produce the Global Multi-Resolution Topography (GMRT) synthesis – a continuously updated digital elevation model that is accessible through Open Geospatial Consortium (OGC; www.opengeospatial.org) Web services. GMRT had its genesis in 1992 with the NSF RIDGE Multibeam Synthesis (RMBS); later grew to include the Antarctic Multibeam Synthesis (AMBS); expanded again to include the NSF Ridge 2000 and MARGINS programs; and finally emerged as a global compilation in 2005 with the NSF Legacy of Ocean Exploration (LOE) project. The LOE project forged a permanent partnership between MGDS and NGDC, in which swath bathymetry data sets are routinely published and exchanged via the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH; www.openarchives.org). GMRT includes both color-shaded relief images and underlying elevation values at ten different resolutions as high as 100m. New data are edited, gridded, and tiled using tools originally developed by William Haxby at Lamont-Doherty Earth Observatory. Global and regional data sources include the NASA Shuttle Radar Topography Mission (SRTM; http://www.jpl.nasa.gov/srtm/); Smith & Sandwell Satellite Predicted Bathymetry (http://topex.ucsd.edu/marine_topo/); SCAR Subglacial Topographic Model of the Antarctic (BEDMAP; http://www.antarctica.ac.uk/bedmap/); and International Bathymetric Chart of the Arctic Ocean (IBCAO; http://www.ngdc.noaa.gov/mgg/bathymetry/arctic/). Local data sources include high-resolution bathymetry swaths and grids from over 210 research cruises, submersible dives, and related compilations to date. GMRT is accessible via a OGC Web Map Service (WMS) which offers dynamic resolution and on-the-fly map re- projection. A growing number of commercial and open-source clients support OGC protocols, including recent versions of Google Earth and Google Maps which now support WMS natively. GMRT is incorporated as a primary basemap in science Web portals and geobrowsers including EarthChem (www.earthchem.org) and GeoMapApp (www.geomapapp.org), which also serves the underlying elevation values. Future development work will include extension of GMRT to higher resolutions; addition of the International Bathymetric Chart of the Southern Ocean (IBCSO; www.ibcso.org) and the improved SRTM V2; and deployment of new OGC services including a Web Coverage Service (WCS) and Web Terrain Service (WTS). http://www.marine-geo.org/
IN51B-0406
Improving Marine Geophysical Data Quality
The 4,918 marine geophysics cruises currently archived at the National Geophysical Data Center's trackline archive comprise the primary global database for marine gravity, bathymetry, and magnetics. Many of these cruises fed the plate tectonic revolution of the 1960s and 1970s and remain valuable today as the cost of seagoing research continues to rise without alternative methods for obtaining comparable resolution. Although these data are of tremendous value to scientists, their affective use is limited by a significant amount of error within the archive. To ensure the continued use of these data we have completed a thorough along-track analysis of the archive. We find ~5-10% of marine gravity and bathymetry records erroneous and estimate that magnetic errors may exceed twice this proportion. By flagging extreme navigation errors, systematic errors such as invalid metadata and incorrectly scaled or offset data, temporary instrument malfunctions, and by recomputing invalid free-air and magnetic anomalies, we obtain an "internally consistent" data set suitable for more rigorous Crossover Error (COE) analysis. Rather than overwrite original cruise files, we compile extreme problems detected along-track into "E77" errata tables which we generate for each cruise. E77 tables will be made available via the web to facilitate sharing of corrections amongst scientists. Upon removal of extreme internal errors, we perform updated global COE analyses of marine gravity and bathymetry as well as the first global COE analysis of marine magnetics to date. Whereas E77 tables are static and may be easily shared and updated when necessary, COE tables are ephemeral and evolve as new cruises are added. Here we report preliminary COE findings and present examples of obvious errors correctable using COE correction tables.