Book Chapters

Our concern is with the statistical description of paleomagnetic vectors and the estimation of their mean and variance. These vectors may come from a number of different rock units or archeological samples, representing a range of acquisition times, and be useful for studies of the mean paleomagnetic field and paleosecular variation; alternatively, the vectors may come from individual...

When studying the mean and variance of paleomagnetic data it is a common practice to employ principal component analysis (Jolliffe, 2002). The theory of this method is related to the mathematics quantifying the moment of inertia of a set of particles of mass about some reference point of interest. For the purposes of data analysis, principal component analysis was first promoted by...

The Geomagnetism Program of the US Geological Survey has, for over a century now, monitored the Earth's magnetic field through a network of magnetic observatories and conducted scientific analysis on the data collected. The program traces its origins to the Reorganization Act of 1843, in which Congress authorized the creation of a coastal survey agency, as part of the Treasury Department...

Magnetic indices are simple measures of magnetic activity that occurs, typically, over periods of time of less than a few hours and which is recorded by magnetometers at ground‐based observatories (Mayaud, 1980; Rangarajan, 1989; McPherron, 1995). The variations that indices measure have their origin in the Earth's ionosphere and magnetosphere. Some indices having been designed...

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The Pliocene spans the interval of Earth history from ca. 5.3 to 1.8 million years ago (Ma). Although details are still debated there is much evidence from continental and oceanic locations indicating that conditions from 5.3 to about 3.0 Ma were often warmer than in modern times in mid- and high latitudes and that climate variability was subdued compared to the Pleistocene. Millennial...

A key difficulty in developing accurate, science-based conceptual models for remediation of contaminated field sites is the proper accounting of multiple coupled geochemical and hydrologic processes. An example of such a difficulty is the separation of desorption and dissolution processes in releasing contaminants from sediments to groundwaters; very few studies are found in the...

Flood lavas, by definition, cover vast areas in great sheets of lava, without the construction of major edifices (e.g., Geikie, 1880; Washington, 1922; Tyrrell, 1937; Self et al., 1997). The flat terrain that flood lavas produce has led to the term “plateau volcanism” to be used as a synonym for flood volcanism. In addition, the classic erosion pattern of flood lavas leaves a series of...

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Interest in the generation of tsunamis by submarine mass movements has warranted a reassessment of their distribution and the nature of submarine landslides offshore of the eastern U.S. The recent acquisition and analysis of multibeam bathymetric data over most of this continental slope and rise provides clearer view into the extent and style of mass movements on this margin. Debris...

To date, the majority of evidence indicates that most subsurface environments possess climax ecological communities that are well adapted to the environment in which they live. Like their counterparts on the surface, subsurface ecosystems are characterized by a high degree of microbiological diversity, they possess trophic structure, and they exhibit material cycling and energy transfer...