Collaborative Research: Developing A Prototype Drifter to Measure the Oceanic Geomagnetic Field

Woods Hole Oceanographic Institution, Woods Hole MA

Investigators

Abstract

The PI's request funding to build an inexpensive magnetic drifter that works well for a typical, hypothesis-driven NSF project that studies a specific region. They envision a mode of data collection where investigators release a flotilla of inexpensive surface drifters upstream of an area they wish to study with magnetic field data. The drifters pass over the study site, collecting the desired data. These relatively, small, low power and inexpensive magnetic sensors can be obtained and combined or integrated with the circuitry within the drifter. Because the drifter moves slowly, the magnetometer can be set up to read the geomagnetic field infrequently keeping the data rate low. Magnetic field data from the oceans have been critical for understanding the origin, evolution and structure of the ocean basins. The marine magnetic stripe anomalies not only document Earth?s magnetic field polarity reversals but also form the basis for the Geomagnetic Polarity Timescale and are used to reconstruct the history of the ocean basins. These anomalies are best resolved by sea surface magnetic measurements. Satellite magnetic measurements, while global in extent, lack the lateral resolution to resolve these magnetic stripe anomalies in detail. While we have a working knowledge of most of the ocean basins there are areas, such as the southern ocean, that have only sparse shiptrack coverage. In a recent global compilation for the World Digital Magnetic Anomaly Map (WDMAM, Purucker, 2007) the available data was so sparse that a model of magnetic anomalies was used to help interpolate data. Shiptime is expensive and global coverage in remote areas is simply not feasible in the near future. The solution we believe is to use the proven technology of ocean drifters and floats used by the physical oceanographic community and mount small, low power, inexpensive magnetometer sensors to these drifters to cover areas of the ocean that are undersampled at present. Broader Impacts: The main broader impact emphasized in the proposal seems mainly the advanced training of a post-doc; and potentially involving a summer undergraduate student. Clearly the ability to collect much-needed geomagnetic data at a fraction of the cost of ship time would have broad impacts in the geosciences community. The proposal will support a female postdoctoral fellow. Data obtained will be used by many other researchers and have a broad impact throughout the tectonics community.