Only a few paleornagnetic data are available on Mexican rocks (Pal and Urrutia, 1977). Urrutia, and Pal (1977) based on a study of Tertiary rocks from Jalisco have pointed out the possibility of tectonic rotation of Mexico with respect to…

A review of solar activity minima and the relationship of the auroral and geomagnetic activities suggest that solar minima are not evident in the available data., Una revisión de las mínimas de actividad solar y la relación entre la actividad…

The proposed method corrects for inhomogeneity in the azimuthal distribution of stations, by fitting the residuals to a cosine function of the azimuth. Early arrivals are assigned greater weights than late arrivals. The weights are optimized experimentally by using data…

Data from µ-meson telescopes, at different underground depths, have been compared with the predictions of a solar-controlled mechanism proposed by Swinson. The observations at ground level and at moderate depths show a significant field-polarity dependent effect of the kind envisaged…

Uranium, Thorium and Potassium contents of some igneous and sedimentary rocks of the Guanajuato Mineral District have been measured by γ-ray scintillation spectrometry. Preliminary measurements show that the area studied is not a province of high radioactive contents. The data…

This paper deals with the necessity of implementing a new electric ground conductivity map for planning and development of a medium-wave broadcasting service in Mexico. The use of the Field Attenuation Method with a methodology that simplifies the operations and…

El Cinturón Volcánico Transmexicano (CVM) es la zona que en la actualidad presenta la mayor actividad volcánica en la región sur de México. En este trabajo se emplea un método no tradicional para calcular el flujo de calor por medio…

Bajo condiciones prometido de turbidez se obtuvieron grandes variaciones en los parámetros de turbidez atmosférica (exponente de longitud de onda α y coeficiente de turbidez β) adoptando la técnica usual de Angstrom, empleando la representación gráfica de valores de intensidad…

A comparative study of the solar wind in the Venus ionosheath, based on the Mariner 5, Venera 9 and 10, and Pioneer Venus spacecraft, is presented. It is shown that the available experimental evidence indicates that, downstream from the bow…

Contents of alkali (K, Rb and Cs) and alkaline earth (Ba and Sr) elements as well as 87Sr/86Sr ratios are reported for eight selected samples of basalt and andesite from Chichinautzin Sierra and one sample of older dacite from this…