World-wide digital well log data collected for the Ocean Drilling Program (ODP) by Schlumberger Offshore Services under contract to Texas A&M University. The data were in turn converted to ASCII form and released to NGDC for longterm archival by the Borehole Research Group (BRG) of the Lamont-Doherty Earth Observatory, Columbia University. Some of the data parameters contained in the data files relate to conductivity, bulk density, porosity, resistivity, grain density, and sonic ratio. Other parameters are present and may vary for each well log.

The NOAA National Centers for Environmental Information (formerly National Geophysical Data Center) maintains an active database of worldwide geomagnetic observatory data to further the understanding of Earth magnetism and the Sun-Earth environment.Historically, magnetic observatories were established to monitor the secular change (variation), of the Earth's magnetic field, and this remains one of their most important functions. This generally involves absolute measurements sufficient in number to monitor instrumental drift and to produce annual means.

Yearbook for Italian Geomagnetic Observatories

This data file is comprised of instantaneous values of the geomagnetic components D, H, and Z or X, Y, and Z at 2.5-minute intervals. These values were derived from analog recordings (magnetograms) with the aid of semi-automatic digitizing equipment from a worldwide network of about 75 observatories.

This file is comprised of absolute mean hourly values of the geomagnetic components D, H and Z or X, Y and Z. These values, on magnetic tape, are available from approximately 220 of the 400 worldwide observatories which have ever operated. Most of the values were hand-scaled from the analog recordings (magnetograms) and were added to the file via punched cards. From some observations, for more recent years, there are means of values recorded directly on

The file is comprised of instantaneous absolute values of the geomagnetic components D, H, and Z or X, Y, and Z at 1-minute intervals. These values were derived either from analog recordings (magnetograms) with the aid of semiautomatic digitizing equipment or from digital recordings made directly on magnetic tape. These data are available from about 50 observatories operated by the United States, Canada, Australia, Japan, United Kingdom, Taiwan, Sodankayla,
Iceland, Finland and France.

These data are generated as part of the International Magnetospheric Study. The file consists of 10-second instantaneous measurements for the geomagnetic components D, H, X, Y, Z and R. The 10 second values were collected digitally in real time by a network of 26 ground observatories and relayed to the Space Environment Center, Boulder, Colorado, via the SMS-GOES satellite and the Wallops Island, Virginia ground station. The 1-minute average values are

This data file was generated as part of the International Magnetospheric Study (IMS). The file consists of values of the geomagnetic components D, H, X, Y, Z, and R averaged from 10-second instantaneous measurements. The 1-minute average values are computed at the Space Environment Center (SEC) in Boulder, Colorado, on the SELDADS computer system. The 10-second values are collected digitally in real time at the ground observatories and relayed to SEC via the

This data set was generated by the Finish Academy of Science from magnetic data collected during the International Magnetospheric Study, 1976-1978. The data were collected by an array of digital magnetometers located in Finland. The data are values of the earth's magnetic field components X, Y, and Z. The values are recorded on magnetic tape in BINARY format.

The NOAA National Centers for Environmental Information (formerly National Geophysical Data Center) receives magnetograms from over 200 geomagnetic observatories. The Center archives data from 1867 to the present, however the primary holdings are from 1957 to the present. The archives contain over 5,000 reels of 35 mm microfilm copies of magnetograms. Magnetograms are records obtained from an instrument known as a magnetometer which is designed to measure small variations in the components of the geomagnetic field. There are two types of magnetometers, the La Cour and the Ruska.