Publications
Geomagnetism publications.
Filter Total Items: 414
Holocene geomagnetic secular variation recorded by volcanic deposits at Mount St. Helens, Washington
A compilation of paleomagnetic data from volcanic deposits of Mount St. Helens is presented in this report. The database is used to determine signature paleomagnetic directions of products from its Holocene eruptive events, to assign sampled units to their proper eruptive period, and to begin the assembly of a much larger database of paleomagnetic directions from Holocene volcanic rocks in western
Authors
J. T. Hagstrum, R. P. Hoblitt, C. A. Gardner, T.E. Gray
Magnetic fields over active tectonic zones in ocean
The aim of our work is to estimate the electromagnetic effects that can be detected in the submarine zones with hydrothermal activity. It is known that meso-scale flows appear in the regions over underwater volcanoes or hot rocks. Their origin is connected with heat flux and hot jets released from underwater volcanoes or faults in a sea bottom. Values of mean velocities and turbulent velocities in
Authors
Yu. A. Kopytenko, P.M. Serebrianaya, L.V. Nikitina, A.W. Green
Revised ages for tuffs of the Yellowstone Plateau volcanic field: Assignment of the Huckleberry Ridge Tuff to a new geomagnetic polarity event
40Ar/39Ar ages were determined on the three major ash-flow tuffs of the Yellowstone Plateau volcanic field in the region of Yellowstone National Park in order to improve the precision of previously determined ages. Total-fusion and incremental- heating ages of sanidine yielded the following mean ages: Huckleberry Ridge Tuff—2.059 ± 0.004 Ma; Mesa Falls Tuff— 1.285 ± 0.004 Ma; and Lava Creek Tuff—
Authors
M. A. Lanphere, D. E. Champion, R. L. Christiansen, G. A. Izett, J.D. Obradovich
Relocation of Wyoming mine production blasts using calibration explosions
An important requirement for a comprehensive seismic monitoring system is the capability to accurately locate small seismic events worldwide. Accurate event location can improve the probability of determining whether or not a small event, recorded predominantly by local and regional stations, is a nuclear explosion. For those portions of the earth where crustal velocities are not well established,
Authors
Carol A. Finn, Gordon D. Kraft, Matthew S. Sibol, Ronald L. Jones, Mark E. Pulaski
The derivation of World Magnetic Model 2000
This report contains a detailed summary of the data used, the modelling techniques employed and the results obtained in the production of the World Magnetic Model 2000. This model is designed for use in air and sea navigation systems and is valid till 2005.0. The derivation of World Magnetic Model 2000 has been the joint responsibility of the British Geological Survey (BGS) and the United States G
Authors
Susan Macmillan, John M. Quinn
The 2000 revision of the joint UK/US geomagnetic field models and an IGRF 2000 candidate model
The method of derivation of the joint UK/US spherical harmonic geomagnetic main-field and secular-variation models is presented. Early versions of these models, with the main field truncated at degree 10, are the UK/US candidates for the IGRF 2000 model. The main-field model describes the Earth’s magnetic field at the 2000.0 epoch, while the secular-variation model predicts the evolution of this f
Authors
S. Macmillan, J.M. Quinn
Book review: Geomagnetism. (Research: Past and Present)
Book information: Geomagnetism. (Research: Past and Present)" Wilfried Schröder, editor, 2000. Science Edition /IDCH-IAGA, Darmstadt Germany. 248 p.
Authors
Edward A. Mankinen
Scaling laws from geomagnetic time series
The notion of extended self-similarity (ESS) is applied here for the X-component time series of geomagnetic field fluctuations. Plotting nth order structure functions against the fourth order structure function we show that low-frequency geomagnetic fluctuations up to the order n = 10 follow the same scaling laws as MHD fluctuations in solar wind, however, for higher frequencies (f > 1/5[h]) a cle
Authors
Z. Voros, P. Kovacs, A. Juhasz, A. Kormendi, A.W. Green
Automated detection of Pi 2 pulsations using wavelet analysis: 1. Method and an application for substorm monitoring
Wavelet analysis is suitable for investigating waves, such as Pi 2 pulsations, which are limited in both time and frequency. We have developed an algorithm to detect Pi 2 pulsations by wavelet analysis. We tested the algorithm and found that the results of Pi 2 detection are consistent with those obtained by visual inspection. The algorithm is applied in a project which aims at the nowcasting of s
Authors
M. Nose, T. Iyemori, M. Takeda, T. Kamei, D. K. Milling, D. Orr, H. J. Singer, E. W. Worthington, N. Sumitomo
The 1995 revision of the joint US/UK geomagnetic field models - I. Secular variation
We present the methods used to derive mathematical models of global secular variation of the main geomagnetic field for the period 1985 to 2000. These secular-variation models are used in the construction of the candidate US/UK models for the Definitive Geomagnetic Reference Field at 1990, the International Geomagnetic Reference Field for 1995 to 2000, and the World Magnetic Model for 1995 to 2000
Authors
S. Macmillan, D.R. Barraclough, J.M. Quinn, R.J. Coleman
The 1995 revision of the joint US/UK geomagnetic field models. II: Main field
This paper presents the 1995 main-field revision of the World Magnetic Model (WMM-95). It is based on Project MAGNET high-level (??? 15,000 ft.) vector aeromagnetic survey data collected between 1988 and 1994 and on scalar total intensity data collected by the Polar Orbiting Geomagnetic Survey (POGS) satellite during the period 1991 through 1993. The spherical harmonic model produced from these da
Authors
J.M. Quinn, R.J. Coleman, S. Macmillan, D.R. Barraclough
On the watch for geomagnetic storms
Geomagnetic storms, induced by solar activity, pose significant hazards to satellites, electrical power distribution systems, radio communications, navigation, and geophysical surveys. Strong storms can expose astronauts and crews of high-flying aircraft to dangerous levels of radiation. Economic losses from recent geomagnetic storms have run into hundreds of millions of dollars. With the U.S. Geo
Authors
Arthur W. Green, William M. Brown