A geomagnetic secular variation study (31000-19 500 bp) in Western Canada

Four centuries of geomagnetic secular variation from historical records

We present a new model of the magnetic ­ eld at the core{mantle boundary for the interval 1590{1990. The model, called gufm1, is based on a massive new compilation of historical observations of the magnetic ­ eld. The greater part of the new dataset originates from unpublished observations taken by mariners engaged in merchant and naval shipping. Considerable attention is given to both correcti...

Secular Variation of the Aurora for the past 500 Years

Knowledge of solar variability and its effects on the Earth is essential since the Sun affects almost every aspect of our lives. Direct observations of the Sun, usually of sunspots, with some continuity, exist only since about 1700. Understanding of long-term solar variability must then depend on proxy data, such as visual auroral observations, measurements of magnetic activity, and the radioca...

Investigation of a secular variation impulse using satellite data: The 2003 geomagnetic jerk

Observatory monthly means provide an excellent opportunity to study the temporal changes of the magnetic field at a given location. Unfortunately, the uneven distribution of the present observatory network makes it difficult to determine the global field change pattern. Recently, we have developed an approach to extract satellite monthly means at a regular network of “virtual observatories” at ...

Fractal Analysis for Geomagnetic Secular Variations

Long-Term Seafloor Electromagnetic Observation in the Northwest Pacific May Detect the Vector Geomagnetic Secular Variation

Sea Floor ElectroMagnetic Stations (SFEMSs) are now operating at two deep seafloor sites called the 'WPB' and the 'NWP' in the West Philippine Basin and the Northwest Pacific Basin, respectively. One of the main objectives of the SFEMSs is to detect the geomagnetic secular variations on the deep seafloor where long-term geomagnetic observations have not so far been achieved. SFEMSs can measure ...