Publications

The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed at the observatory; therefore it should be regarded as preliminary.

The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed at the observatory; therefore it should be regarded as preliminary.

The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed at the observatory; therefore it should be regarded as preliminary.

The cataclysmic eruption of Mount St. Helens May 18, 1980, removed 2.9 km2 (about 0.13 km3) of glacier snow and ice including a large part of Shoestring, Forsyth, Wishbone, Ape, Nelson, and all of Loowit and Leschi Glaciers. Minor eruptions and bulging of the volcano from March 27 to May 17 shattered glaciers which were on the deforming rock and deposited ash on other glaciers. Thick ash...

Outflow channels on Mars1 are long sinuous linear depressions that occur mostly in the equatorial area (±30° lat.). They differ from small valley networks2 by being larger and arising full born from chaotic terrains. Outflow channels resemble terrestrial stream beds, and their origin has generally been attributed to water3–5 in catastrophic floods6,7 or mudflows8. The catastrophic-flood...

Recently, the National Research Council published a report by the Panel on National, Regional, and Local Seismograph Networks of the Committee on Seismology in which the principal recommendation was for the establishment of a national digital seismograph network (NDSN). The Panel Report (Bolt, 1980) addresses both the need and the scientific requirements for the new national network. The...

The preliminary geomagnetic data included here is made available to scientific personnel and organizations, as part of a cooperative effort and on a data exchange basis because of the early need by some users. To avoid delay, all of the data is copied from original forms processed at the observatory; therefore it should be regarded as preliminary.

Eleven small lakes were formed by landslides caused by the 1929 Buller earthquake in New Zealand; four others were formed by other historic earthquakes in this country. At least nine other New Zealand lakes are dammed by landslides and were probably formed by prehistoric earthquakes. Earthquake-dammed lakes could provide an estimate of paleoseimicity for the past few hundred or thousand...

In 1976, the U.S. Geological Survey conducted the Atlantic Margin Coring Project (AMCOR) to obtain information on stratigraphy, hydrology and water chemistry, mineral resources other than petroleum hydrocarbons, and geotechnical engineering properties at sites widely distributed along the Continental Shelf and Slope of the Eastern United States (Hathaway and others, 1976, 1979). This...

For a year of quiet solar-activity level, geomagnetic records from American hemisphere observatories located between about 0?? and 30?? north geomagnetic latitude were used to compare the annual and semiannual variations of the geomagnetic field associated with three separate contributions: (a) the quiet-day midnight level, MDT; (b) the solar-quiet daily variation, Sq; (c) the quiet-time...

The plot of 210Pb activity against depth in carbonate sands on the Virgin Island Bank is a negative asymmetric hyperbolic curve. As depth increases, an initial rapid decrease in 210Pb activity caused by the decay of unsupported 210Pb and 226Ra is followed by increasing activity as a result of 210Pb achieving equilibrium with in growing 230Th. As this curve is time dependent, an estimate...

No abstract available.