This reference encompasses the fields of Geomagnetism and Paleomagnetism in a single volume. Both sciences have applications in navigation, in the search for minerals and hydrocarbons, in dating rock sequences, and in unraveling past geologic movements such as plate motions they have contributed to a better understanding of the Earth. The book describes in fine detail the current state of knowledge and provides an up-to-date synthesis of the most basic concepts. It is an indispensable working tool not only for geophysicists and geophysics students but also for geologists, physicists, atmospheric and environmental scientists, and engineers.

Originally published in 1995, Monitoring Active Volcanoes is a comprehensive text which addresses the importance of volcano surveillance in the context of forecasting eruptive activity and mitigating its effects. The traditional core of seismic and ground deformation monitoring is discussed, along with more innovative techniques involving the recording of microgravity and micromagnetic variations, and the changing compositions of volcanic gases and liquids. The role of satellites is stressed, particularly with regard to the capabilities for measuring surface deformation, recognizing thermal anomalies and monitoring gas and ash plumes from space platforms. This book provides an invaluable insight into how and why volcanoes are monitored. It will be of interest to volcanologists, geophysicists and earth scientists.

Treatise on Geophysics, Second Edition, is a comprehensive and in-depth study of the physics of the Earth beyond what any geophysics text has provided previously. Thoroughly revised and updated, it provides fundamental and state-of-the-art discussion of all aspects of geophysics. A highlight of the second edition is a new volume on Near Surface Geophysics that discusses the role of geophysics in the exploitation and conservation of natural resources and the assessment of degradation of natural systems by pollution. Additional features include new material in the Planets and Moon, Mantle Dynamics, Core Dynamics, Crustal and Lithosphere Dynamics, Evolution of the Earth, and Geodesy volumes. New material is also presented on the uses of Earth gravity measurements. This title is essential for professionals, researchers, professors, and advanced undergraduate and graduate students in the fields of Geophysics and Earth system science. Comprehensive and detailed coverage of all aspects of geophysics Fundamental and state-of-the-art discussions of all research topics Integration of topics into a coherent whole

Advances in Archaeological Method and Theory

An investigation of ultra low frequency electromagnetic signals known as magnetotelluric micropulsations was made. The electric field strength at the earth's surface was measured by means of electrodes placed in the ground. Analog paper chart records of these signals were made at Trinidad, B.W.I., Puerto Rico, and Austin, Texas. These records were later hand-digitized. The power spectra of the signals at each station were computed for a data sample three quarters of an hour long. Certain power spectral peaks in the frequency range from .01 cps to .25 cps were noted. Several previously undiscovered regularities in the spectra of this sample were found. Power spectral peaks occurred at .05, .125, .175, and .225 cps. Also computed were coherencies between signals at all stations. Coherencies above .8 were found between signals recorded at stations more than 2,000 miles apart. The regular features found in the power spectra were also noted in the coherencies. In addition, some spectral line splitting was not obvious in the power spectra appeared in the coherencies. From the evidence presented it is concluded that certain frequency bands of micropulsations are simultaneous over great distances, and probably originate in the outer atmosphere. (Author).