Three sites from the vent area and one at the tip of the 1870 flow provided well-constrained directions.
This is also true for Ceboruco lava flow, and overall mean directions and palaeointensities were then used for palaeomagnetic dating applying the Matlab tool and the global palaeosecular variation model SHA. For the 1870 lava flow, the dating resulted in an age ranging between 17 AD (95 per cent probability level), which includes the real emplacement age.
Geomagnetic observatories are providing observations of magnetic field intensity and directions since nearly 200 years.
Worldwide magnetic observatory data are available from international programmes like INTERMAGNET and World Data Centers.
Certain minerals in rocks lock-in a record of the direction and intensity of the magnetic field when they form.
This record provides information on the past behavior of Earth's magnetic field and the past location of tectonic plates.
Paleomagnetism (or palaeomagnetism in the United Kingdom) is the study of the record of the Earth's magnetic field in rocks, sediment, or archeological materials.Another application of our results lies in geomagnetic dating of archaeological material or lava flows and sediment cores, which are used, e.g., for environmental or climate studies.