cooperation project for the development of regional magnetic models

and charts in Mexico and Costa Rica

Ana Caccavari-Garza1, Gerardo Cifuentes-Nava1, Esteban

Hernández-Quintero1, Jorge Brenes2, Armando


(1)Instituto de

Geofísica, Universidad Nacional Autónoma de México, México (2)

Instituto Costarricense de Electricidad, Costa Rica



Mexico and Costa Rica are countries that have studied the Geomagnetic

field in the region since the end of the 19th century, providing

valuable information for the study of the Earth's magnetic field and

its variations, both regionally and globally.

In Costa Rica, systematic observations of the magnetic field begin

between 1898 and 1901 by Henri Pittier, who carried out measures of

declination and horizontal component, publishing the first isogonic

chart. There are magnetic declination data obtained in engineering

works in Guatemala, El Salvador, Honduras, Nicaragua and Costa Rica

(1891-1983). In 1965, Gutiérrez Braun published a updated isogonic

and in 1978 G. Leandro and J. Páez make the most detailed study of

the magnetic field of Costa Rica, obtaining the magnetic chart for

1978 that was updated later by G. Leandro in 1984.

In Mexico, the first magnetic observations were made at the end of the

16th century by Cavendish in 1576 in La Paz, B.C and the first

Magnetic chart was published by the Carnegie Institute in Washington

in 1906. In the year of 1947, was founded the IGEF (Institute of

Geophysics of the UNAM) and was commissioned to publish the Magnetic

Charts for the Mexican Republic. The last published Magnetic Chart

corresponds to the Epoch 2010.0, constituted by 52 Magnetic Stations

of Repetition. There are also a couple of catalogs published by the

Institute of Geophysics of the National Autonomous University of

Mexico, where we can find all the magnetic values of the Mexican

Republic and Central America of 1587-1991.

These studies have been interrupted in recent years due to problems of

lack of logistical and financial support; as well as the operation of

the Chiripa Magnetic Observatory, Costa Rica, which has being

reinstalled in a new zone and started working again this year.

In this project we takes up these important studies and we work

together to occupy a number adequate repeating magnetic stations in

the area (Costa Rica and Mexico), with two purposes principal: update

data for regional geomagnetic field models (Southeast of Mexico and

Central America); as well as the exchange of techniques for

measurement, processing, and publication of the results in the

corresponding catalogs that incorporate magnetic cartography in maps.

Collaboration with other countries in this type of project is

extremely important for the solution of problems common, and continue

with the generation of regional knowledge, which also contributes to

the study of the Earth's magnetic field in a global way and supports

new applications such as risk volcanic.

We present the Declination, Inclination and Intensity charts obtained

in different stages of the project as well as the methodology followed

to standardize a protocol of measurements and data processing in both