National Geophysical Data Center and British Geological Survey Update World Magnetic Model [December 15, 2014]
NOAA officials announced today that the World Magnetic Model (WMM)—a representation of Earth’s large-scale magnetic field—has been updated. For the last 10 years, NOAA's National Geophysical Data Center (NGDC) and the British Geological Survey have co-developed the updated WMM, which is an indispensable complement to GPS devices used by the North Atlantic Treaty Organization (NATO) and the US and UK militaries as well as in civil applications ranging from mineral exploration to smartphone apps.
Changes in the Earth’s outer core trigger unpredictable changes in its magnetic field—an invisible force that extends from Earth's interior to where it meets a stream of charged particles emanating from the sun. For example, over the past few decades, the North magnetic pole has been drifting toward Siberia at an irregular speed. This migration can adversely affect the accuracy of navigation if not compensated for by an updated WMM.
Updated every five years using satellite observations of the Earth’s magnetic field, the WMM provides accurate magnetic field declination—the difference between true north and magnetic north—which is critical for navigational safety. Scientists continuously survey the magnetic field and can precisely map the present field and its rate of change and then extrapolate changes into the future. WMM-corrected magnetic compass readings are not subject to ionospheric disturbances and work everywhere, including under the sea and in deep canyons.
NGDC also provides multiple online tools to estimate current and past values of the magnetic field. Our new smartphone app, NOAA's CrowdMag, allows you to turn your smartphone into a traveling magnetic observatory. Available for iOS and Android systems, CrowdMag includes a calculator that uses the WMM to provide magnetic declination, dip angle, total field, and other magnetic field components for any date or location.
National Geophysical Data Center (NGDC) Participates in NOAA Multi-media science briefing on the 2004 Indian Ocean Tsunami [December 08, 2014]
Paula Dunbar from NGDC will participate in a multi-media science briefing on the 2004 Indian Ocean tsunami hosted by NOAA on December 8, 2014. The briefing will include visualizations on NOAA's Science on a Sphere presented to 30 D.C.-area reporters as they prepare articles and broadcast packages for the 10-year anniversary of this international tragedy. The 2004 tsunami was the worst tsunami disaster in history with more than 220,000 deaths in 14 countries. The source of the Indian Ocean tsunami was the December 26, 2004 magnitude 9.1 Mw Sumatra-Andaman earthquake, the third largest earthquake ever recorded. The reporters will hear from the NOAA Tsunami program manager about where we were in 2004 and where we are today on tsunami preparedness. They will also hear from a NOAA tsunami forecaster who was on the forecast desk in Hawaii at NOAA's Pacific Tsunami Warning Center on December 26, 2004. They will hear an amazing survivor's account from a biologist at NOAA Fisheries who was a tourist in Thailand and swept away in the wave. A NOAA researcher will present the latest research and new technologies for tsunami detection and warning. NGDC's Paula Dunbar will describe the development of the NGDC historical tsunami database and how these data are used in hazard assessments, for verification and validation of tsunami models, and for guidance by the tsunami warning centers. NGDC is the national archive and access provider for tsunami data and information and develops seamless topographic-bathymetric digital elevation models for coastal flood forecast and mapping.
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