Declination magnetic charts for Mexico since 1907.0 to 2010.0

We present the construction of magnetic declination charts corresponding to five epochs for last one hundred years; this was result of recovery and statistical analysis of historical magnetic data. The charts were made with the records of magnetic repeat stations reoccupation, distributed throughout the country, the goal was to observe and study the geomagnetic field morphology and their space-temporal variations in Mexico. We aimed to systematize an optimal numerical method for the spatial estimation to minimize the error given the average data for any Mexican magnetic chart: forty magnetic repeat stations and only one magnetic observatory. Also, the charts were compared with the original charts made in its corresponding epoch. The charts quality was improved and the historic geomagnetic information preserved, considering the invaluable record of historical magnetic measurements that exist in Mexico.